A replication of “A quasi-maximum likelihood approach for large, approximate dynamic factor models”

none1siThe authors replicate and extend the Monte Carlo experiment presented in Doz, Giannone and Reichlin (A Quasi-Maximum Likelihood Approach For Large, Approximate Dynamic Factor Models, Review of Economics and Statistics, 2012) on alternative (time-domain based) methods for extracting dynamic factors from large datasets; they employ open source software and consider a larger number of replications and a wider set of scenarios. Their narrow sense replication exercise fully confirms the results in the original article. As for their extended replication experiment, the authors examine the relative performance of competing estimators under a wider array of cases, including richer dynamics, and find that maximum likelihood (ML) is often the dominant method; moreover, the persistence characteristics of the observable series play a crucial role and correct specification of the underlying dynamics is of paramount importanceopenRiccardo LucchettiLucchetti, Riccard

Peer victimization in Primary School. Gender difference

Purpose: The peer victimization is frequent phenomenon in the school. The aim of study was to investigate the gender distinction in the peer victimization, also considering the role that physical activity inside and outside school could have in this phenomenon. Methods: The study included 277 students (142 females; 134 males), between the ages of 8 and 10, attending the primary school. A questionnaire based on "Multi-dimensional Peer-Victimization Scale (MPVS)'' (Mynard et al., 2000), Italian version (Scarpa et al, 2010) and adapted to the age of the subjects, was given, to evaluate four areas of victimization (physical victimization, verbal victimization, social manipulation and attack on property). In addition, subjects were asked which physical activities they practiced in and out of school. Results: The results showed that the phenomenon victimization is present in a content way, and that males are more involved than females. Physical victimization falls more in the male gender (average value of 2±1.4 and 1.6±0.9 for the males and females, respectively), while the social manipulation in the women gender (average value of 1.9±1.2 and 1.7±1.1 for the females and males, respectively). The correlation between two or more macro-areas is there for the 74.32% of the cases and verbal victimization is the most widespread phenomenon in our sample (9.46%). The extra-school physical activity is performed by the majority of students (83.57%). Conclusions: The results confirm existing studies in the literature. The peer victimization includes not only being the obvious target of physical attacks but also includes more subtle forms of abuse, falling more in females behavior than in males

Brazilian scientific articles on “Spirituality, Religion and Health”

Abstract Background Studies on “Spirituality, religion and health” (R/S) have been increasing worldwide, including in Brazil. Mapping this production can help researchers to understand this field and also to identify gaps in the Brazilian R/S studies. Objective To analyze the Brazilian scientific articles on “Religion, Spirituality and Health” available on the main electronic databases using a bibliometric approach. Methods A comprehensive review of four major databases (PubMed, Scopus, BVS and Web of Science) was conducted. Three reviewers performed the data analysis. Off-topic articles, articles from Portugal, books and thesis were excluded. Articles were then classified by: Publication year, journal, Central focus in R/S, Academic Area, Main topic and Study Type. Results From 3,963 articles found, 686 studies were included in the final analysis (320 had central focus on R/S). There was an increase of articles in the last decade (most observational), with predominance of mental health issues, and from journals in the field of psychiatry, public health and nursing. Discussion This study enabled us to widen our understanding about how the field of “spirituality, religion and health” has been established and how this field is increasing in Brazil. These findings can help in the development of future Brazilian studies

Length–weight relationships of bivalve species in Italian razor clam Ensis minor (Chenu, 1843) (Mollusca: Bivalvia) fishery

Length–weight relationships of bivalve species collected during razor clam (Ensis minor) surveys along Italian coastal waters (Northern Adriatic and Tyrrhenian Sea) in the 3-year period 2016–2018 are reported. A total of 13,588 individuals, belonging to 12 bivalve species and 20 populations between the Adriatic and Tyrrhenian Seas, were sampled for this study. Analyzing growth parameters for each population, we found 11 allometries and nine isometries. About half of the species investigated showed different growth characteristics between the two areas

Pots vs trammel nets: A catch comparison study in a Mediterranean small-scale fishery

Passive bottom-set nets are the most widely used fishing gears in Mediterranean small-scale fisheries (SSFs). Trammel nets, in particular, have key advantages such as their ease of use and handling and high capture efficiency for numerous commercial species. However, they entail high discard rates (5\u201344% of the total catch) connected to high mortality, thus exerting an adverse impact on benthic communities, besides catching individuals of commercial species under the minimum conservation reference size (MCRS) and specimens of protected species. Fish pots are seen as alternative and a more sustainable gear type that allow reducing discards in SSFs. In this study, a collapsible pot was tested at three coastal sites in the north-western Adriatic Sea (GFCM GSA 17) to compare its catch efficiency with that of the local traditional trammel nets. Data analysis demonstrated a similar catch efficiency for the commercial species, both among sites and as a whole. Moreover, the trammel net caught a larger amount of discards, both in terms of species number and of CPUEW. The catch comparison study involved the two most abundant landed species, common cuttlefish Sepia officinalis and annular sea bream Diplodus annularis. The pots were more effective for S. officinalis, whereas the trammel net was more effective for the shorter length classes for D. annularis, which were mostly under the MCRS (12 cm). The innovative pots could provide a valuable alternative to the trammel nets traditionally used in the Adriatic Sea, at least in certain areas and periods. Their main advantages include that they do not require a different rigging and they can be used without bait, while their foldable design allows large numbers to be easily loaded on board SSF vessels. The results of this pilot study indicate that pots can achieve the objectives of reducing discards and bycatch in SSFs without penalizing the catch of commercial species

Stability in Linear Optimization Under Perturbations of the Left-Hand Side Coefficients

This paper studies stability properties of linear optimization problems with finitely many variables and an arbitrary number of constraints, when only left hand side coefficients can be perturbed. The coefficients of the constraints are assumed to be continuous functions with respect to an index which ranges on certain compact Hausdorff topological space, and these properties are preserved by the admissible perturbations. More in detail, the paper analyzes the continuity properties of the feasible set, the optimal set and the optimal value, as well as the preservation of desirable properties (boundedness, uniqueness) of the feasible and of the optimal sets, under sufficiently small perturbations.Research supported by the grants: BASAL PFB-03 (Chile), FONDECYT 1130176 (Chile) and MTM2011-29064-C03-01 (Spain). Research supported by the grant MTM2014-59179-C2-1-P (Spain) and the Discovery Projects DP120100467 and DP110102011 (Australian Research Council). Research supported by the MIUR project ’Variational and Topological Methods in the Study of Nonlinear Phenomena” (2009)

Polarization Coupling between Ferroelectric Liquids and Ferroelectric Solids: Effects of the Fringing Field Profile

Recent experiments devoted to characterizing the behavior of sessile ferroelectric liquid droplets on ferroelectric solid substrates have shown the existence of a droplet electromechanical Rayleigh-like instability. The instability is induced by the bulk polarization of the ferroelectric fluid, which couples to the polarization of the underlying substrate through its fringing field and solid-fluid interface coupling. With the aim of characterizing this phenomenon, namely the coupling between the polarizations of a fluid and a solid material, we studied the behavior of ferroelectric liquid droplets confined between two solid substrates, arranged in different configurations, realized to generate fringing fields with different profiles. The results show that the features of the droplets instability are indeed affected by the specific fringing field shape in a way dominated by the minimization of the electrostatic energy associated with the bulk polarization of the ferroelectric fluid