A family-based approach to preventing excessive weight gain

Objective: Preventing weight gain in adults and excessive weight gain in children is a high priority. We evaluated the ability of a family‐based program aimed at increasing steps and cereal consumption (for breakfast and snacks) to reduce weight gain in children and adults. Research Methods and Procedures: Families (n = 105) with at least one 8‐ to 12‐year‐old child who was at‐risk‐for‐overweight or overweight (designated as the target child) were recruited for the study. Eighty‐two families were randomly assigned to receive the family‐based intervention and 23 families to the control condition. The 13‐week intervention consisted of specific increases in daily steps (an additional 2000 steps/d) and consumption of 2 servings/d of ready‐to‐eat cereal. Results: The intervention was successful in increasing walking (steps) and cereal consumption. The intervention had positive, significant effects on percentage BMI‐for‐age and percentage body fat for target children and weight, BMI, and percentage body fat for parents. On further analysis, the positive effects of the intervention were seen largely in target girls and moms, rather than in target boys and dads. Discussion: This family‐based weight gain prevention program based on small changes holds promise for reducing excessive weight gain in families and especially in growing overweight children.     

Spatial proximity between two host plant species influences oviposition and larval distribution in a leaf beetle

Everything else being equal, insect herbivores can be expected to oviposit on host plants that provide the qualitatively and quantitatively best food for larvae. However, the selection of a plant for oviposition may be influenced by such ecological factors as natural enemies, host distribution, host patch size or host patch density. We performed a field study to test whether spatial proximity between two host plant species influences the oviposition patterns and larval distribution of the alpine leaf beetle Oreina elongata. In the population studied, O. elongata oviposits and feeds on two host plants, that belong to the same family (Asteraceae): Adenostyles alliariae and Cirsiumspinosissimum. The first species contains pyrrolizidine alkaloids that are sequestered by the beetle as a chemical defence, whereas the second plant does not contain any alkaloids but has hairy and spiny leaves that might give some mechanical protection to beetle larvae.
During two consecutive summers, we quantified oviposition and larval distribution on randomly chosen C. spinosissimum that grew spatially isolated from A. alliariae, on C. spinosissimum that grew in leaf contact with A. alliariae and on A. alliariae that grew in leaf contact with C. spinosissimum (isolated A. alliariae was not considered, because it is rare in the study population). In both years, more eggs were laid on C. spinosissimum than on A. alliariae and more on those C. spinosissimum that were growing close to A. alliariae than on those growing isolated. Large numbers of larvae moved from C. spinosissimum to A. alliariae during the season. Patch size did not influence egg and larval numbers. Eggs survived better on C. spinosissimum than on A. alliariae in the field. The data suggest that C. spinosissimum may provide eggs with better protection against stormy weather. In a separate study of the same population, we found that larval performance was better on A. alliariae than on C. spinosissimum. Our present data suggest that O. elongata preferentially oviposits on plants of the species that maximizes egg survival and that grow in close proximity to plants of the species that provides better food and chemical defence.     

Relative Ability of Orally Administered Lactobacillus murinus To Predominate and Persist in the Porcine Gastrointestinal Tract

Five porcine-derived Lactobacillus or Pediococcus isolates administered to pigs (n = 4), either singly or as a combination at ~10¹⁰ CFU per day varied with respect to intestinal survival and persistence. Two Lactobacillus murinus strains survived best and were excreted at ~10⁷ to 10⁸ CFU/g of feces. In contrast, Pediococcus pentosaceus DPC6006 had the lowest fecal count at ~10⁵ CFU/g and was excreted at a significantly lower level than both L. murinus strains. Fecal L. murinus DPC6003 counts were also significantly higher than both Lactobacillus salivarius DPC6005 and Lactobacillus pentosus DPC6004 (~10⁶ CFU/g). The L. murinus strains persisted for at least 9 days postadministration in both the feces and the cecum. Animals fed a combination of all five strains excreted ~10⁷ CFU of the administered strains/g, with L. murinus predominating, as determined by randomly amplified polymorphic DNA PCR. Postadministration, variation was observed between animals fed the strain combination, but in general, L. murinus DPC6002 and DPC6003 and L. pentosus DPC6004 predominated in the feces and the cecum while P. pentosaceus DPC6006 was detected only in the cecum. Fifteen days after the start of culture administration, mean fecal Enterobacteriaceae counts were significantly lower in some of the treatment groups. In addition, when mean preadministration counts were compared with those obtained after 21 days of culture administration, Enterobacteriaceae counts were reduced by ~87 to 98% in pigs fed L. salivarius DPC6005, P. pentosaceus DPC6006, L. pentosus DPC6004, and the culture mix. In conclusion, the porcine intestinal isolates have potential as probiotic feed additives for pigs, with differences in strain performance highlighting the advantages of using culture combinations.     

The magnesium inhibition and arrested phagosome hypotheses: new perspectives on the evolution and ecology of Symbiodinium symbioses

Zooxanthella symbioses are arguably the most important ecological interaction on coral reefs because they energetically subsidize the entire community, and enhance the calcification process that provides structure for all other organisms. While we have developed a detailed understanding of the diversity among and within the Symbiodinium clades, we currently lack a mechanistic explanation for which factors favoured zooxanthella invasion of the intracellular habitat in heterotrophic hosts, and for what molecular mechanisms permit residence within the cell. We propose two hypotheses that explain important evolutionary and ecological features of zooxanthella symbioses. The magnesium inhibition hypothesis (MIH) states that increases in the Mg/Ca ratio in sea water that occurred over the last 100 million years created a situation where Mg(2+) inhibited Ca(2+) transport to zooxanthellae. The MIH predicts, among other things, that the intracellular niche was invaded as a response to this abiotic stressor. The arrested phagosome hypothesis (APH) states that Symbiodinium spp. mimic host cell endosomal digestive machinery via the symbiosome to appear like digesting prey through perpetual release of zooxanthella-derived compounds. The APH represents a subtle but important distinction from previous hypotheses regarding interactions between symbiont and host at the cellular level. The APH predicts that symbionts tune rates of material release to match expectations of host cellular machinery. An outcome of the APH is that intra-host residence time becomes a vital parameter to consider. Both hypotheses shift control of the symbiosis away from the host, and instead focus attention on the niche requirements of Symbiodinium spp.     

Characterization of the maize xylem sap proteome

The xylem in plants has mainly been described as a conduit for water and minerals, but emerging evidence also indicates that the xylem contains protein. To study the proteins in xylem sap, we characterized the identity and composition of the maize xylem sap proteome. The composition of the xylem sap proteome in maize revealed proteins related to different phases of xylem differentiation including cell wall metabolism, secondary cell wall synthesis, and programmed cell death. Many proteins were found to be present as multiple isoforms and some of these isoforms are glycosylated. Proteins involved in defense mechanisms were also present in xylem sap and the sap proteins were shown to have antifungal activity in bioassays.