Galaxy Cosmological Mass Function

We study the galaxy cosmological mass function (GCMF) in a semi-empirical relativistic approach using observational data provided by galaxy redshift surveys. Starting from the theory of Ribeiro & Stoeger (2003, arXiv:astro-ph/0304094) between the mass-to-light ratio, the selection function obtained from the luminosity function (LF) data and the luminosity density, the average luminosity $L$ and the average galactic mass $\mathcal{M}_g$ are computed in terms of the redshift. $\mathcal{M}_g$ is also alternatively estimated by a method that uses the galaxy stellar mass function (GSMF). Comparison of these two forms of deriving the average galactic mass allows us to infer a possible bias introduced by the selection criteria of the survey. We used the FORS Deep Field galaxy survey sample of 5558 galaxies in the redshift range $0.5 < z < 5.0$ and its LF Schechter parameters in the B-band, as well as this sample's stellar mass-to-light ratio and its GSMF data. Assuming ${\mathcal{M}_{g_0}} \approx 10^{11} \mathcal{M}_\odot$ as the local value of the average galactic mass, the LF approach results in $L_{B} \propto (1+z)^{(2.40 \pm 0.03)}$ and $\mathcal{M}_g \propto (1+z)^{(1.1\pm0.2)}$. However, using the GSMF results produces $\mathcal{M}_g \propto (1+z)^{(-0.58 \pm 0.22)}$. We chose the latter result as it is less biased. We then obtained the theoretical quantities of interest, such as the differential number counts, to calculate the GCMF, which can be fitted by a Schechter function. The derived GCMF follows theoretical predictions in which the less massive objects form first, being followed later by more massive ones. In the range $0.5 < z < 2.0$ the GCMF has a strong variation that can be interpreted as a higher rate of galaxy mergers or as a strong evolution in the star formation history of these galaxies.Comment: In memory of William R. Stoeger (1943-2014). LaTeX, 8 pages, 7 figures. Minor changes to match version sent to publisher. To appear in "Astronomy and Astrophysics

Predicting social distancing and compulsive buying behaviours in response to COVID-19 in a United Kingdom sample

This study examines differences between key socio-demographic groups and the impact of strength of social network, political trust, and fear of COVID-19 on working from home (a key social distancing behaviour) and compulsive buying (a maladaptive behaviour) in response to COVID-19. This study used a correlational cross-sectional survey design. A sample of 411 participants in the United Kingdom (UK) completed measures of strength of social network, political trust, fear of COVID-19, length of self-isolation and compulsive buying. Results showed that older people and lower income groups are less likely to work from home in response to COVID-19; that people with a diagnosed mental health disorder exhibited less political trust, more fear of COVID-19, and more compulsive buying; and that people reporting COVID-19 symptomatology had been in self-isolation for longer and exhibited more compulsive buying than those with no COVID-19 symptomatology. The structural equation model showed that age, having a diagnosed mental health disorder, having COVID-19 symptomatology and strength of social network impacted on working from home and compulsive buying, through the mediators of political trust, fear of COVID-19 and length of self-isolation. The results demonstrate that some groups in the UK population may be vulnerable to maladaptive behaviours and poor social, psychological, and physical health outcomes as a result of the COVID-19 pandemic. These groups may require special support to cope effectively with the effects of COVID-19

Innovative local policies in Portuguese low-density rural areas

Nowadays, the issue of rural development has a central place on the agenda of policy-makers, prompting a discussion on the instrumental and procedural options of public policies. This paper seeks to contribute to the reflection on the potentialities and limitations of promoting rural development based on innovative strategies sustained by territorial governance modalities, which entail an active involvement of local agents, especially local authorities. For this, it takes as case studies three public policy experiences led by local authorities within a Portuguese low-density region, with one of the lowest development rates among EU regions. Specifically, it aims to discuss: (a) the effectiveness of adopting innovative policies in the context of low-density rural areas; and (2) the role of territorial governance in the success of those policies. The research followed a document analysis and interviews with local development actors. The analysis suggests that peripheral rural areas are not condemned to human desertification. There is a wide spectrum of opportunities for these areas. They can bring together a strategic view of the future, and an institutional leadership capable of dynamizing an adjusted territorial governance model. This is the challenge currently facing rural development policy.info:eu-repo/semantics/publishedVersio