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Biomedical subjects

Y Abel

Publications and source records attributed to Y Abel.

6 recordsLinked to original sources

Home and videotape intervention delays early complementary feeding among adolescent mothers.

BACKGROUND: The American Academy of Pediatrics, the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), and the World Health Organization recommend that infants receive only breast milk or formula for the first 4 to 6 months of life, followed by the introduction of complementary foods. Despite these recommendations, many infants, particularly those with adolescent mothers, receive solid foods (often cereal mixed with formula in a bottle) and liquids other than formula or breast milk in the first few weeks of life. Decisions on early feeding are often guided by grandmothers and influenced by beliefs that infants need complementary food to counteract signals of hunger, reduce crying, and sleep through the night. OBJECTIVE: This investigation evaluated the efficacy of an intervention to delay the early introduction of complementary feeding among first-time, black, adolescent mothers living in multigenerational households. The intervention focused on reducing the cultural barriers to the acceptance of the recommendations of the American Academy of Pediatrics, WIC, and World Health Organization on complementary feeding by highlighting 3 topics: 1) recognition of infants' cues; 2) nonfood strategies for managing infant behavior; and 3) mother-grandmother negotiation strategies. The intervention was delivered through a mentorship model in which a videotape made by an advisory group of black adolescent mothers was incorporated into a home-visiting program and evaluated through a randomized, controlled trial. METHODS: One hundred eighty-one first-time, low-income, black mothers <18 years old, living in multigenerational households were recruited from 3 urban hospitals. Infants were born at term, with birth weight appropriate for gestational age and no congenital problems. Shortly after delivery, mothers and grandmothers completed a baseline assessment and mothers were randomized into an intervention or control group. Intervention group mothers received home visitation every other week for 1 year. At 3 months, a subset of 121 adolescent mothers reported on their infant's intake through a food frequency questionnaire. Mothers who fed their infant only breast milk, formula, or water were classified as optimal feeders. Mothers who provided complementary foods other than breast milk, formula, or water were classified as less optimal feeders. RESULTS: Sixty-one percent of the infants received complementary foods before 3 months old. Multivariate hierarchical logistic regression was used to evaluate the determinants of being in the optimal versus less optimal feeders group. After controlling for infant age and family income, mothers of infants in the optimal feeders group were more likely to report accurate messages from WIC regarding the timing of complementary food and nearly 4 times more likely to be in the intervention group. The most common complementary food was cereal mixed with formula in the bottle. CONCLUSIONS: The success of this relatively brief intervention demonstrates the importance of using ecological theory and ethnographic research to design interventions that enable participants to alter their behavior in the face of contradictory cultural norms. The intervention focused on interpreting infants' cues, nonfood methods of managing infant behavior, and mother-grandmother negotiations. It was delivered through methods that were familiar and acceptable to adolescent mothers-a mentorship model incorporating home visits and videotape. The skill-oriented aspects of the intervention delivered in a culturally sensitive context may have enabled the young mothers to follow the guidelines that they received from WIC and from their pediatricians. Strategies, such as those used in this intervention, may be effective in promoting other caregiving recommendations, thereby enabling providers to meet the increasing demands from parents for advice regarding children's early growth and development.

Adolescent↗

On the evolutionary origin of the plant mitochondrion and its genome.

Higher plants occupy very different positions in the mitochondrial and nuclear lineages of global phylogenetic trees based on conserved regions of small subunit (SSU) and large subunit (LSU) rRNA sequences. In the nuclear subtree, plants branch off late, at a position reflecting a massive radiation of the major multicellular (and some unicellular) groups; in the mitochondrial subtree, in contrast, plants branch off early, near the point of connection between the mitochondrial and eubacterial lineages. Moreover, in the nuclear lineage, plants branch together with the unicellular green alga Chlamydomonas reinhardtii, whereas in the mitochondrial lineage (in both SSU and LSU trees), metaphytes and chlorophyte branch separately. Statistical evaluation indicates that the anomalous branching position of higher plants in the mitochondrial lineage is not a treeing artifact attributable to the relatively rapid rate of sequence divergence of non-plant mitochondrial rRNA sequences. In considering alternative biological explanations for these results, we are led to propose that the rRNA genes in plant mitochondria may be of more recent evolutionary origin than the rRNA genes in other mitochondria. This proposal has implications for monophyletic vs. polyphyletic scenarios of mitochondrial origin and is consistent with other evidence indicating that plant mtDNA is an evolutionary mosaic.

Journal Article↗

The evolutionary relationships among known life forms.

Sequences of small subunit (SSU) and large subunit (LSU) ribosomal RNA genes from archaebacteria, eubacteria, and the nucleus, chloroplasts, and mitochondria of eukaryotes have been compared in order to identify the most conservative positions. Aligned sets of these positions for both SSU and LSU rRNA have been used to generate tree diagrams relating the source organisms/organelles. Branching patterns were evaluated using the statistical bootstrapping technique. The resulting SSU and LSU trees are remarkably congruent and show a high degree of similarity with those based on alternative data sets and/or generated by different techniques. In addition to providing insights into the evolution of prokaryotic and eukaryotic (nuclear) lineages, the analysis reported here provides, for the first time, an extensive phylogeny of the mitochondrial lineage.

Base Sequence↗