Behavioural change box? Applying the COM-B model to understand behavioural triggers that support consumption of fruits and vegetable among subscribers of a fruit and vegetable box scheme

OBJECTIVE: To understand the key mechanisms that support healthy dietary habits promoted by fruit and vegetable (F&V) box schemes, testing relevant behaviour change triggers identified under the COM-B model in an evaluation research study of a Portuguese F&V box scheme (PROVE). DESIGN: Correlation study with a post-test-only non-equivalent group design based on survey data. The mechanisms underpinning the differences between subscribers and non-subscribers are operationalised as mediation effects. Data availability, theoretical relevance and empirical validation supported the selection and testing of four potential mediators for the effects of subscribing to the box scheme on F&V consumption. These estimations derive from the coefficients of a structural equation model combined with the product coefficient approach and Sobel test. SETTING: The study is part of a wider evaluation study on the impact of the PROVE box scheme on sustainability, health and equity. PARTICIPANTS: A sample of PROVE box subscribers (n 294) was compared with a matched subsample of non-subscribers (n 571) in a nationally representative survey. RESULTS: Subscribing to the PROVE box correlates with an increased probability of eating at least five portions of F&V, irrespective of differences in age, education and perceived economic difficulties. Diet quality perceptions, and more robustly, the strength of meal habits and household availability were identified as relevant mediators. CONCLUSIONS: The subscription to an F&V box scheme is connected with proximal context that enables the consumption of F&V by ensuring more readily available F&V and better situational conditions associated with healthier meal habits

Repression of RNA polymerase by the archaeo-viral regulator ORF145/RIP

Little is known about how archaeal viruses perturb the transcription machinery of their hosts. Here we provide the first example of an archaeo-viral transcription factor that directly targets the host RNA polymerase (RNAP) and efficiently represses its activity. ORF145 from the temperate Acidianus two-tailed virus (ATV) forms a high-affinity complex with RNAP by binding inside the DNA-binding channel where it locks the flexible RNAP clamp in one position. This counteracts the formation of transcription pre-initiation complexes in vitro and represses abortive and productive transcription initiation, as well as elongation. Both host and viral promoters are subjected to ORF145 repression. Thus, ORF145 has the properties of a global transcription repressor and its overexpression is toxic for Sulfolobus. On the basis of its properties, we have re-named ORF145 RNAP Inhibitory Protein (RIP)

Dual‐band, Dual‐polarized Reflectarray antenna in Ku Band

This paper presents a dual-band single layer printed reflectarray antenna with closely separated frequency bands centered at 12 and 14 GHz. The novel unit cell, with which the antenna has been designed, consists of a printed cross-dipole and a split ring element mounted on the same substrate, providing the antenna with dual polarization capability at both bands. The antenna is composed of 17 × 17 elements printed on a square plate with area of 20 × 20 cm2. In order to facilitate the simulations, the antenna has been designed as center-fed configuration, having the beam direction at broadside at both frequencies. However, the antenna can be designed to have arbitrary beam shapes at each frequency which makes it an attractive option to be employed in satellite communication systems. © 2012 IEEE