Options for near-term phaseout of CO(2) emissions from coal use in the United States.

The global climate problem becomes tractable if CO(2) emissions from coal use are phased out rapidly and emissions from unconventional fossil fuels (e.g., oil shale and tar sands) are prohibited. This paper outlines technology options for phasing out coal emissions in the United States by approximately 2030. We focus on coal for physical and practical reasons and on the U.S. because it is most responsible for accumulated fossil fuel CO(2) in the atmosphere today, specifically targeting electricity production, which is the primary use of coal. While we recognize that coal emissions must be phased out globally, we believe U.S. leadership is essential. A major challenge for reducing U.S. emissions is that coal provides the largest proportion of base load power, i.e., power satisfying minimum electricity demand. Because this demand is relatively constant and coal has a high carbon intensity, utility carbon emissions are largely due to coal. The current U.S. electric grid incorporates little renewable power, most of which is not base load power. However, this can readily be changed within the next 2-3 decades. Eliminating coal emissions also requires improved efficiency, a "smart grid", additional energy storage, and advanced nuclear power. Any further coal usage must be accompanied by carbon capture and storage (CCS). We suggest that near-term emphasis should be on efficiency measures and substitution of coal-fired power by renewables and third-generation nuclear plants, since these technologies have been successfully demonstrated at the relevant (commercial) scale. Beyond 2030, these measures can be supplemented by CCS at power plants and, as needed, successfully demonstrated fourth-generation reactors. We conclude that U.S. coal emissions could be phased out by 2030 using existing technologies or ones that could be commercially competitive with coal within about a decade. Elimination of fossil fuel subsidies and a substantial rising price on carbon emissions are the root requirements for a clean, emissions-free future.

Growth and development of preterm infants fed infant formulas containing docosahexaenoic acid and arachidonic acid.

OBJECTIVES: To evaluate safety and benefits of feeding preterm infants formulas containing docosahexaenoic acid (DHA) and arachidonic acid (ARA) until 92 weeks postmenstrual age (PMA), with follow-up to 118 weeks PMA. STUDY DESIGN: This double-blinded study of 361 preterm infants randomized across three formula groups: (1) control, no supplementation; (2) algal-DHA (DHA from algal oil, ARA from fungal oil); and (3) fish-DHA (DHA from fish oil, ARA from fungal oil). Term infants breast-fed > or =4 months (n = 105) were a reference group. Outcomes included growth, tolerance, adverse events, and Bayley development scores. RESULTS: Weight of the algal-DHA group was significantly greater than the control group from 66 to 118 weeks PMA and the fish-DHA group at 118 weeks PMA but did not differ from term infants at 118 weeks PMA. The algal-DHA group was significantly longer than the control group at 48, 79, and 92 weeks PMA and the fish-DHA group at 57, 79, and 92 weeks PMA but did not differ from term infants from 79 to 118 weeks PMA. Supplemented groups had higher Bayley mental and psychomotor development scores at 118 weeks PMA than did the control group. Supplementation did not increase morbidity or adverse events. CONCLUSIONS: Feeding formulas with DHA and ARA from algal and fungal oils resulted in enhanced growth. Both supplemented formulas provided better developmental outcomes than unsupplemented formulas.

Growth, efficacy, and safety of feeding an iron-fortified human milk fortifier.

OBJECTIVE: Survival rates for preterm infants who weigh between 501 and 1500 g at birth have continued to improve over time. In response to this continuing decrease in birth weight of surviving preterm infants, Enfamil Human Milk Fortifier has recently been reformulated to meet the nutritional requirements of these smaller, more rapidly growing infants. It now provides an increased protein level of 1.1 g/58 kJ, a decreased carbohydrate level of 0.2 g/58 kJ, and a combined linoleic and alpha-linolenic fatty acid content of 157 mg/58 kJ. As these very small preterm infants have an increased requirement for dietary iron, the fortifier has been supplemented with 1.44 mg/58 kJ of iron, an amount of iron similar to that provided in a typical iron-fortified term infant formula. An iron-fortified product obviates the need for administration of an iron supplement, a hyperosmolar-inducing intervention. The purpose of this prospective, double-blind, randomized, controlled study was to evaluate growth, safety, and efficacy in a population of very low birth weight (VLBW) preterm infants who received human milk fortified with either the reformulated iron-fortified powdered human milk fortifier test product (HMF-T) or a powdered commercially available human milk fortifier control product (HMF-C). METHODS: Infants who weighed < or =1500 g, had a gestational age < or =33 weeks postmenstrual age, and had an enteral intake of at least 100 mL/kg per day of unfortified human milk were stratified by gender and birth weight and randomized to receive HMF-T or HMF-C product from study day 1 to study day 28, hospital discharge, or the termination of human milk feedings, whichever came first. Unless medically indicated, investigators were not to administer iron supplements from study days 1 to 14. Infants were assessed serially for growth; enteral and parenteral intake; serum chemistry and hematologic values; clinical histories, including the administration of blood transfusions; feeding tolerance; respiratory outcomes; and morbidities, including adverse events. RESULTS: Of the 181 participating infants in this study, 96 received HMF-T and 85 received HMF-C. At randomization, there were no significant differences in infant characteristics between the fortifier groups. The percentage of participants who remained in the study for 28 days was similar between fortifier groups (57% HMF-T, 46% HMF-C). For both fortifier groups, the most frequent reasons for discontinuing the study before study day 28 were unavailability of human milk and hospital discharge. Rate of weight gain was similar between the fortifier groups (17.5 +/- 0.53 g/kg per day for HMF-T and 17.3 +/- 0.59 g/kg per day for HMF-C). Mean achieved weight, length, and head circumference were comparable between groups across the 28-day study period. Total protein intake from enteral and parenteral nutrition was significantly greater for the HMF-T fortifier group; however, this difference did not result in any difference in growth between the 2 fortifier groups. An analysis of the growth and energy intake data of a subset of the intent-to-treat population who adhered more strictly to the study feeding protocol yielded results similar to those seen for the intent-to-treat population. There were no clinically significant differences in the results of laboratory studies between the groups at study days 0, 14, and 28. Anemia of prematurity was prevalent in both study groups; by study day 28, median hematocrit levels were 27.0% (interquartile range [IQR]: 24.0%-29.6%) for the HMF-T group and 26.0% (IQR: 24.0%-31.0%) for the HMF-C group. Median ferritin levels were 77.0 ng/mL (IQR: 37-155 ng/ml) for HMF-T and 92.0 ng/mL (IQR: 33-110 ng/mL) for HMF-C. There were no significant differences between the study fortifier groups in regard to the receipt of medically indicated iron supplements on or before study day 14 or in the administration of blood transfusions before study day 0 or from study days 0 through 14. However, from study day 15 to study day 28, fewer HMF-T infants (n = 12) required a blood transfusion than did HMF-C infants (n = 20). Although the higher levels of iron in the HMF-T fortifier (1.44 mg vs 0.35 mg for HMF-C per 4 packets of powdered fortifier) did not prevent anemia per se, it did reduce the frequency of one of the most serious outcomes of anemia: the need for a blood transfusion. There was no statistically significant difference between fortifier groups in regard to feeding tolerance. Rates of suspected sepsis (26% HMF-T vs 31% HMF-C) and confirmed sepsis (5% HMF-T, 7% HMF-C) were low as were the rates of suspected necrotizing enterocolitis (NEC; 6% HMF-T and 5% HMF-C) and confirmed Bell's stage 2 or more NEC (1% HMF-T and 1% HMF-C). There were no statistically significant differences between the study fortifier groups in regard to the incidence of confirmed and suspected sepsis and NEC. CONCLUSION: Both human milk fortifiers studied are safe, are well tolerated, and facilitate comparable good growth; however, using the iron-fortified product may reduce the need for blood transfusions in VLBW infants. The similar low rates of suspected and confirmed NEC and sepsis seen in both fortifier groups in this study refutes the premise that the inclusion of iron in fortifiers will increase the incidence of sepsis and NEC. Indeed, the incidence for NEC and sepsis for both groups in this study was lower than is reported for VLBW infants and similar to that seen for infants who are fed human milk.

Docosahexaenoic acid and arachidonic acid enhance growth with no adverse effects in preterm infants fed formula.

OBJECTIVE: To determine if docosahexaenoic acid (DHA) and arachidonic acid (ARA) supplementation influences growth or visual acuity of formula-fed premature infants. STUDY DESIGN: Double-blind, multi-center study of 194 premature infants given preterm formula with no DHA or ARA (control), 0.15% energy DHA, or 0.14% DHA + 0.27% ARA from single-cell triglycerides for at least 28 days and then fed term formula (no DHA or ARA) to 57 weeks postmenstrual age (PMA), with 90 breast-fed term infants as reference. RESULTS: Infants fed DHA+ARA formula gained weight significantly faster (post-hoc analysis) during preterm formula feeding than control infants (34.7 vs. 30.7 g/d) and had weights and weight:length ratios not different from term breast-fed infants at 48 and 57 weeks PMA. Infants fed control or DHA formula had lower body weights than term infants. Red blood cell phosphatidylethanolamine ARA was significantly correlated to weight gain during preterm formula feeding and to weight and length at 40, 48, and 57 weeks PMA (r = 0.19 to 0.24, P =.004-.02). Providing DHA or DHA+ARA during the preterm period had no effect on subsequent visual acuity or incidence of adverse events. CONCLUSIONS: Feeding DHA+ARA from single-cell triglycerides enhances weight gain in formula-fed premature infants with no evidence of adverse effects.

Nutritional balance studies: evaluation of a premature infant formula

Se evaluó una fórmula infantil para prematuros (Enfamil Premature Formula) de 24 Kcal/oz (81 Kcal/100 ml) con un contenido mineral moderadamente alto (117 mg Ca/dl y 58 mg P/100 ml) y un contenido proteínico de 3 g/100 Kcal, en 16 períodos de balance de tres días de duración cada uno, al 10§ y 21§ día de edad en nueve recién nacidos prematuros cuyo peso al nacer fluctuada entre 1,200 y 1,400 g. La velocidad de crecimiento observada fue similar a la velocidad intrauterina, y la fórmula fue bien aceptada y tolerada. Las retenciones de calcio (62.5%) fueron similares al aumento intrauterino, y la retención de fósforo fue ligeramente menor. Se notó una retención nitrogenada elevada sin desarrollo de acidosis metabólica ni anormalidad en los valores séricos de urea