Development and preliminary validation of the Parenting around SNAcking Questionnaire (P-SNAQ).

Snacking makes significant contributions to children's dietary intake but is poorly understood from a parenting perspective. This research was designed to develop and evaluate the psychometrics of a theoretically grounded, empirically-informed measure of snack parenting. The Parenting around SNAcking Questionnaire (P-SNAQ) was developed using a conceptual model derived from current theory and mixed-methods research to include 20 hypothesized snack parenting practices along 4 parenting dimensions (autonomy support, structure, coercive control and permissiveness). Expert panel evaluation and cognitive interviews were used to refine items and construct definitions. The initial instrument of 105 items was administered to an ethnically diverse, low-income sample of 305 parents (92% mothers) of children aged 1-6 y participating in three existing cohort studies. The sample was randomly split into two equal samples. Exploratory factor analysis was conducted with the first sample to identify snack parenting practices within each parenting dimension, followed by confirmatory factor analysis with the second sample to test the hypothesized factor structure. Internal consistency of sub-scales and associations with existing measures of food parenting practices and styles and child weight status were evaluated. The final P-SNAQ scale included 51 items reflecting 14 snack parenting practices across four parenting dimensions. The factor structure of the P-SNAQ was consistent with prior theoretical frameworks. Internal consistency coefficients were good to very good for 12 out of 14 scales and subscale scores were moderately correlated with previously validated measures. In conclusion, initial evidence suggests that P-SNAQ is a psychometrically sound measure for evaluating a wide range of snack parenting practices in young children.

Classifying foods in contexts: how adults categorize foods for different eating settings.

This project examined adults' food cognitions by applying schema theory to explain how adults categorized foods for different contexts. Qualitative interviews and repeated card sort activities for different eating contexts were conducted to elicit as many food categories as possible from 42 US adults. Participants labeled card sort piles with their own words, providing 991 card sort labels. Qualitative analysis of the labels resulted in the emergence of 12 category types. Personal-experience-based types were specific to the individual (e.g., Preference). Context-based types were related to situational aspects of eating episodes (e.g., Location). Food-based types were related to intrinsic properties of the foods (e.g., Physical characteristics). Different combinations of the 12 category types were used for different eating contexts. Personal-experience and context-based types were used most frequently overall. Some category types were used more frequently for specific contexts (e.g., Convenience for work contexts). Food-based taxonomic category types were used most frequently when no context was defined. Script-oriented categories were more often used in response to specific eating contexts. These findings provide a framework to consider how individuals classify foods in real-life eating contexts. Attention to personal-experience and context-based category types may help improve understanding of relationships between knowledge and food choice behaviors.

Replication strand preference for deletions associated with DNA palindromes.

We have isolated and sequenced a set of deletions stimulated by DNA palindromes in Escherichia coli. All of the deletions are asymmetric with respect to the parental sequence and have occurred at short direct repeats. This is consistent with deletion by strand slippage during DNA replication. The orientation of the asymmetry in such deletion products is diagnostic of the direction of the strand slippage event. It is therefore also diagnostic of its occurrence on the leading or lagging strand of the replication fork when the direction of replication is known. In all cases in which the orientation of the asymmetry could be determined with respect to DNA replication, the products were consistent with a preference for deletion on the lagging strand of the fork. The data include replication slippage in three situations: on the chromosome of E. coli, in bacteriophage lambda and in high-copy-number pUC-based plasmids.

Different structures of selected and unselected araB-lacZ fusions.

Formation of araB-lacZ coding-sequence fusions is a key adaptive mutation system. Eighty-four independent araB-lacZ fusions were sequenced. All fusions carried rearranged MuR linker sequences between the araB and lacZ domains indicating that they arose from the standard intermediate of the well-characterized Mu DNA rearrangement process, the strand transfer complex (STC). Five non-standard araB-lacZ fusions isolated after indirect sib selection had novel structures containing back-to-back inverted MuR linkers. The observation that different isolation procedures gave rise to standard and non-standard fusions indicates that cellular physiology can influence late steps in the multi-step biochemical sequence leading to araB-lacZ fusions. Each araB-lacZ fusion contained two novel of DNA junctions. The MuR-lacZ junctions showed 'hot-spotting' according to established rules for Mu target selection. The araB-MuR and MuR-MuR junctions all involved exchanges at regions of short sequence homology. More extensive homology between MuR and araB sequences indicates potential STC isomerization a resolvable four-way structure analogous to a Holliday junction. These results highlight the molecular complexity of araB-lacZ fusion formation, which may be thought of as a multi-step cell biology process rather than a unitary biochemical reaction.

DIR: a novel DNA rearrangement associated with inverted repeats.

A novel DNA rearrangement has been characterised that is both a direct and inverted repeat. This rearrangement involves the 2-fold duplication of a plasmid sequence adjacent to the site of insertion of a long palindrome. The sequence of this rearrangement suggests that it has arisen by strand slippage from the leading to the lagging strand of the replication fork as a consequence of the presence of the long palindrome.