Xnrs and Activin Regulate Distinct Genes during Xenopus Development: Activin Regulates Cell Division

BACKGROUND: The mesoderm of the amphibian embryo is formed through an inductive interaction in which vegetal cells of the blastula-staged embryo act on overlying equatorial cells. Candidate mesoderm-inducing factors include members of the transforming growth factor type β family such as Vg1, activin B, the nodal-related proteins and derrière. METHODOLOGY AND PRINCIPLE FINDINGS: Microarray analysis reveals different functions for activin B and the nodal-related proteins during early Xenopus development. Inhibition of nodal-related protein function causes the down-regulation of regionally expressed genes such as chordin, dickkopf and XSox17α/β, while genes that are mis-regulated in the absence of activin B tend to be more widely expressed and, interestingly, include several that are involved in cell cycle regulation. Consistent with the latter observation, cells of the involuting dorsal axial mesoderm, which normally undergo cell cycle arrest, continue to proliferate when the function of activin B is inhibited. CONCLUSIONS/SIGNIFICANCE: These observations reveal distinct functions for these two classes of the TGF-β family during early Xenopus development, and in doing so identify a new role for activin B during gastrulation

Aggressive dominance can decrease behavioral complexity on subordinates through synchronization of locomotor activities

Social environments are known to influence behavior. Moreover, within small social groups, dominant/subordinate relationships frequently emerge. Dominants can display aggressive behaviors towards subordinates and sustain priority access to resources. Herein, Japanese quail (Coturnix japonica) were used, given that they establish hierarchies through frequent aggressive interactions. We apply a combination of different mathematical tools to provide a precise quantification of the effect of social environments and the consequence of dominance at an individual level on the temporal dynamics of behavior. Main results show that subordinates performed locomotion dynamics with stronger long-range positive correlations in comparison to birds that receive few or no aggressions from conspecifics (more random dynamics). Dominant birds and their subordinates also showed a high level of synchronization in the locomotor pattern, likely emerging from the lack of environmental opportunities to engage in independent behavior. Findings suggest that dominance can potentially modulate behavioral dynamics through synchronization of locomotor activities.publishedVersionAlcala, Rocio. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Caliva, Jorge Martín. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Caliva, Jorge Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina.Flesia, Ana Georgina. Facultad de Matemática, Astronomía, Física y Computación; Argentina.Flesia, Ana Georgina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Estudios de Matemática; Argentina.Marin, Raúl Hector. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Marin, Raúl Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina.Kembro, Jackelyn Melissa. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina.Kembro, Jackelyn Melissa. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Biológicas y Tecnológicas; Argentina

Determining the impact of smoking point of sale legislation among youth (Display) study : a protocol for an evaluation of public health policy

This is the provisional PDF of the accepted article. The fully formatted version will be available from the publisher's website.Background: Tobacco advertising and product promotions have been largely banned in the UK but point of sale (POS) tobacco advertising is one of the few places where tobacco products may be legitimately advertised. POS displays have been shown to increase susceptibility to smoking, experimentation and initiation into smoking. These displays may also influence perceived prevalence of smoking and the perception that tobacco products are easily obtained and are a 'normal' product. A ban of POS tobacco advertising was introduced in Scotland in large tobacco retail outlets of over 280m2 internal sales floor areas (mainly supermarkets) in April 2013 and will be extended to include smaller tobacco retail outlets in April 2015. However, the impact of POS bans on smoking attitudes, behaviours and prevalence has yet to be determined. Methods: This study has a multi-modal before and after design and uses mixed methods to collect data, at baseline and then with longitudinal follow-up for 4 years, in four purposively selected communities. For the purposes of the study, community is defined as the catchment areas of the secondary schools selected for study. There are four main components to the on-going study. In each of the four communities, at baseline and in follow-up years, there will be: mapping and spatial analyses of tobacco retail outlets; tobacco advertising and marketing audits of tobacco retail outlets most used by young people; cross-sectional school surveys of secondary school pupils; and focus group interviews with purposive samples of secondary school pupils. The tobacco audit is supplemented by interviews and observations conducted with a panel of tobacco retailers recruited from four matched communities. Discussion: This study examines the impact of the implementation of both a partial and comprehensive ban on point of sale (POS) tobacco advertising on attitudes to smoking, brand awareness, perceived ease of access to tobacco products and youth smoking prevalence. The results will be of considerable interest to policy makers both from the UK and other jurisdictions where they are considering the development and implementation of similar legislation.PostprintPeer reviewe