Eating away-from-home of consumers from Campinas city, Sao Paulo, Brazil

Objective This study analyzed how often non probabilistic sample of individuals ate away from home and the types of establishments they preferred for having lunch. Methods In January 2006, a pretested questionnaire was administered to a non probabilistic sample of 250 consumers (125 males and 125 females) from the municipality of Campinas. The Student's t-test, analysis of variance and Fisher's Least Square Difference were used to identify the significant differences between how often someone has lunch in different places and his opinion on the factors that influence his choice of establishment according to socioeconomic and demographic variables. Results The percentages of individuals that had lunch away from home 4-7 times a week and supper away from home 1-3 times a week were 38.8% and 30.4% respectively. Some consumers (35.2%) reported eating at all-you-can-eat and pay-by-weight buffet-style restaurants frequently or very frequently. One of the factors considered extremely important when choosing the restaurant was employee and facility cleanness. The differences between frequencies and opinions according to socioeconomic and demographic features were statistically significant (p<0.05). Conclusion Consumers usually have lunch at buffet-style restaurants when they eat away from home. Nutrition information programs for consumers about eating away from home should be made available.24229530

Substrate Binding Regulates Redox Signaling in Human DNA Primase

Generation of daughter strands during DNA replication requires the action of DNA primase to synthesize an initial short RNA primer on the single-stranded DNA template. Primase is a heterodimeric enzyme containing two domains whose activity must be coordinated during primer synthesis: an RNA polymerase domain in the small subunit (p48) and a [4Fe4S] cluster-containing C-terminal domain of the large subunit (p58C). Here we examine the redox switching properties of the [4Fe4S] cluster in the full p48/p58 heterodimer using DNA electrochemistry. Unlike with isolated p58C, robust redox signaling in the primase heterodimer requires binding of both DNA and NTPs; NTP binding shifts the p48/p58 cluster redox potential into the physiological range, generating a signal near 160 mV vs NHE. Preloading of primase with NTPs enhances catalytic activity on primed DNA, suggesting that primase configurations promoting activity are more highly populated in the NTP-bound protein. We propose that p48/p58 binding of anionic DNA and NTPs affects the redox properties of the [4Fe4S] cluster; this electrostatic change is likely influenced by the alignment of primase subunits during activity because the configuration affects the [4Fe4S] cluster environment and coupling to DNA bases for redox signaling. Thus, both binding of polyanionic substrates and configurational dynamics appear to influence [4Fe4S] redox signaling properties. These results suggest that these factors should be considered generally in characterizing signaling networks of large, multisubunit DNA-processing [4Fe4S] enzymes

Inter-modelling: From Theory to Practice

Proocedings of: ACM/IEEE 13 th International Conference on Model Driven Engineering Languages and Systems. Oslo, Norway, October 3-8, 2010.We define inter-modelling as the activity of building models that describe how modelling languages should be related. This includes many common activities in Model Driven Engineering, like the specification of model-to-model transformations, the definition of model matching and model traceability constraints, the development of inter-model consistency maintainers and exogenous model management operators. Recently, we proposed a formal approach to specify the allowed and forbidden relations between two modelling languages by means of bidirectional declarative patterns. Such specifications were used to generate graph rewriting rules able to enforce the relations in (forward and backward) model-to-model transformation scenarios. In this paper we extend the usage of patterns for two further inter-modelling scenarios &- model matching and model traceability &- and report on an EMF-based tool implementing them. The tool allows a high-level analysis of specifications based on the theory developed so far, as well as manipulation of traces by compilation of patterns into the Epsilon Object Language.Work funded by the Spanish Ministry of Science (project TIN2008-02081 and grants JC2009-00015, PR2009-0019), the R&D programme of the Madrid Region (project S2009/TIC-1650), the European Commission’s 7th Framework programme (grant #248864 (MADES)), and the Engineering and Physical Sciences Research Council (EPSRC) (grant EP/E034853/1).Publicad

Yeast require redox switching in DNA primase

Eukaryotic DNA primases contain a [4Fe4S] cluster in the C-terminal domain of the p58 subunit (p58C) that affects substrate affinity but is not required for catalysis. We show that, in yeast primase, the cluster serves as a DNA-mediated redox switch governing DNA binding, just as in human primase. Despite a different structural arrangement of tyrosines to facilitate electron transfer between the DNA substrate and [4Fe4S] cluster, in yeast, mutation of tyrosines Y395 and Y397 alters the same electron transfer chemistry and redox switch. Mutation of conserved tyrosine 395 diminishes the extent of p58C participation in normal redox-switching reactions, whereas mutation of conserved tyrosine 397 causes oxidative cluster degradation to the [3Fe4S]^+ species during p58C redox signaling. Switching between oxidized and reduced states in the presence of the Y397 mutations thus puts primase [4Fe4S] cluster integrity and function at risk. Consistent with these observations, we find that yeast tolerate mutations to Y395 in p58C, but the single-residue mutation Y397L in p58C is lethal. Our data thus show that a constellation of tyrosines for protein-DNA electron transfer mediates the redox switch in eukaryotic primases and is required for primase function in vivo

Functional and structural similarity of human DNA primase [4Fe4S] cluster domain constructs

The regulatory subunit of human DNA primase has a C-terminal domain (p58C) that contains a [4Fe4S] cluster and binds DNA. Previous electrochemical analysis of a p58C construct revealed that its affinity for DNA is sensitive to the redox state of the [4Fe4S] cluster. Concerns about the validity of this conclusion have been raised, based in part on differences in X-ray crystal structures of the p58C_(272-464) construct used for that study and that of a N-terminally shifted p58C_(266-456) construct and consequently, an assumption that p58C_(272-464) has abnormal physical and functional properties. To address this controversy, a new p58C_(266-464) construct containing all residues was crystallized under the conditions previously used for crystallizing p58C_(272-464), and the solution structures of both constructs were assessed using circular dichroism and NMR spectroscopy. In the new crystal structure, p58C_(266-464) exhibits the same elements of secondary structure near the DNA binding site as observed in the crystal structure of p58C_(272-464). Moreover, in solution, circular dichroism and ^(15)N,^1H-heteronuclear single quantum coherence (HSQC) NMR spectra show there are no significant differences in the distribution of secondary structures or in the tertiary structure or the two constructs. To validate that the two constructs have the same functional properties, binding of a primed DNA template was measured using a fluorescence-based DNA binding assay, and the affinities for this substrate were the same (3.4 ± 0.5 μM and 2.7 ± 0.3 μM, respectively). The electrochemical properties of p58C_(266-464) were also measured and this p58C construct was able to engage in redox switching on DNA with the same efficiency as p58C_(272-464). Together, these results show that although p58C can be stabilized in different conformations in the crystalline state, in solution there is effectively no difference in the structure and functional properties of p58C constructs of different lengths

The [4Fe4S] cluster of human DNA primase functions as a redox switch using DNA charge transport

DNA charge transport chemistry offers a means of long-range, rapid redox signaling. We demonstrate that the [4Fe4S] cluster in human DNA primase can make use of this chemistry to coordinate the first steps of DNA synthesis. Using DNA electrochemistry, we found that a change in oxidation state of the [4Fe4S] cluster acts as a switch for DNA binding. Single-atom mutations that inhibit this charge transfer hinder primase initiation without affecting primase structure or polymerization. Generating a single base mismatch in the growing primer duplex, which attenuates DNA charge transport, inhibits primer truncation. Thus, redox signaling by [4Fe4S] clusters using DNA charge transport regulates primase binding to DNA and illustrates chemistry that may efficiently drive substrate handoff between polymerases during DNA replication