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Objective: To investigate the efficacy and safety of the 'smart' tracheal occlusion (Smart-TO) device in fetal lambs with diaphragmatic hernia (DH).Methods: DH was created in fetal lambs on gestational day 70 (term, 145 days). Fetuses were allocated to either pregnancy continuation until term (DH group) or fetoscopic endoluminal tracheal occlusion (TO), performed using the Smart-TO balloon on gestational day 97 (DH + TO group). On gestational day 116, the presence of the balloon was confirmed on ultrasound, then the ewe was walked around a 3.0-Tesla magnetic resonance scanner for balloon deflation, which was confirmed by ultrasound immediately afterwards. At term, euthanasia was performed and the fetus retrieved. Efficacy of occlusion was assessed by the lung-to-body-weight ratio (LBWR) and lung morphometry. Safety parameters included tracheal side effects assessed by morphometry and balloon location after deflation. The unoccluded DH lambs served as a comparator.Results: Six fetuses were included in the DH group and seven in the DH + TO group. All balloons deflated successfully and were expelled spontaneously from the airways. In the DH + TO group, in comparison to controls, the LBWR at birth was significantly higher (1.90 (interquartile range (IQR), 1.43-2.55) vs 1.07 (IQR, 0.93-1.46); P = 0.005), while on lung morphometry, the alveolar size was significantly increased (mean linear intercept, 47.5 (IQR, 45.6-48.1) vs 41.9 (IQR, 38.8-46.1) μm; P = 0.03); whereas airway complexity was lower (mean terminal bronchiolar density, 1.56 (IQR, 1.0-1.81) vs 2.23 (IQR, 2.14-2.40) br/mm2 ; P = 0.005). Tracheal changes on histology were minimal in both groups, but more noticeable in fetal lambs that underwent TO than in unoccluded lambs (tracheal score, 2 (IQR, 1-3) vs 0 (0-1); P = 0.03).Conclusions: In fetal lambs with DH, TO using the Smart-TO balloon is effective and safe. Occlusion can be reversed non-invasively and the deflated intact balloon expelled spontaneously from the fetal upper airways. © 2020 International Society of Ultrasound in Obstetrics and Gynecology. [ABSTRACT FROM AUTHOR] more...

Wisconsin Quality Synthetic (WQS) is a maize population that has undergone four cycles of S2-topcross selection for increased silage yield and feed quality. This study evaluated forage yield and quality for each cycle of WQS per se as well as testcrosses to two Stiff Stalk-type testers. Linear improvement was seen in whole plant yield, stover yield, and whole-plant quality both in the population per se and in testcrosses. stover quality has not improved through selection. Starch content has increased while crude protein has decreased. Milk yields on a Mg dry matter and hectare basis have increased with selection. Changes in silage dry matter yield have been greater on a percent basis than changes in silage quality, suggesting that the current selection protocol of selecting S2-top crosses first for yield then for quality may be more efficient at improving yield than quality. Selection directly focused on stover quality may be necessary if more rapid improvement in stover composition is desired. [ABSTRACT FROM AUTHOR] more...

Maize hybrids with improved stover yield and quality are needed to support the emerging cellulosic biofuels industry. Knowledge of the genetic variation, covariation, and genetic architecture of agronomic and cell wall traits will help maize breeders improve relevant traits through selective breeding and genetic engineering. We utilized the maize intermated B73 × Mo17 (IBM) recombinant inbred line (AlL) population to map quantitative trait loci (QTL) and to evaluate the genetic relationships among traits relevant for cellulosic biofuel production, including grain yield, stover yield, neutral detergent fiber digestibility (NDFD), and glucan, xylan, and hgnm concentration. Intermated B73 × Mo17 AlL were evaluated per se and as testcrosses to W604S to assess how well performance and QTL effects correspond between inbreds and hybrids. There were no unfavorable correlations between agronomic and cell wall traits within the testcross progeny. Polysaccharide content was either positively correlated to, or not correlated to, NDFD, indicating that increasing both carbohydrate content and convertibility is feasible. Quantitative trait loci were identified for all traits evaluated, but few QTL were in common between inbred per se and testcross evaluations despite moderate to high genotypic correlations between progeny types. This study provides information that will support the development of dual-purpose maize hybrids that are high in grain yield and also high in yield of digestible cellulosic feedstock. [ABSTRACT FROM AUTHOR] more...

The use of maize (Zea mays L.) stover as a feedstock for cellulosic biofuels production will create demand for maize hybrids with greater stover yield. It is expected that grain yield will remain the most critical trait and continue to drive hybrid sales, requiring that any increases in stover yield be made without sacrificing grain yield potential. The objective of this review was to determine the relationship between grain yield, harvest index, and stover yield to illuminate the potential for increasing both grain and stover yield through breeding. In contrast to what has been observed in other crops, gains in maize grain yield over time in the U.S. Corn Belt have been accompanied by increases in stover yield. Where recurrent selection on grain yield has been most successful, stover yield also increased while harvest index has been relatively stable. The opposite situation has been observed in tropical germplasm, where gains in grain yield have been associated with increasing harvest index and relatively constant biomass yield. We expect that stover yield of Corn Belt hybrids will continue to increase along with grain yield, resulting in future hybrids capable of producing both more food and biofeedstock for energy production. If maize breeders pursue selection for increased stover yield, we found no evidence to suggest that breeding for stover yield will necessarily reduce rate of gain in grain yield. [ABSTRACT FROM AUTHOR] more...

Maize (Zea mays L.) stover has been identified as an important feedstock for the production of cellulosic ethanol. Our objectives were to measure hybrid effect and combining ability patterns of traits related to cellulosic ethanol production, determine if germplasm and mutations used for silage production would also be beneficial for feedstock production, and examine relationships between traits that are relevant to selective breeding. We evaluated grain hybrids, germplasm bred for silage production, brown-midrib hybrids, and a leafy hybrid. Yield and composition traits were measured in four environments. There was a 53% difference in stover yield between commercial grain hybrids that were equivalent for other production- related traits. Silage germplasm may be useful for increasing stover yield and reducing lignin concentration. We found much more variation among hybrids than either in vitro ruminal fermentability or polysaccharide concentration. Correlations between traits were mostly favorable or nonexistent. Our results suggest that utilizing standing genetic variation of maize in breeding programs could substantially increase the amount of biofuels produced from stover per unit area of land. [ABSTRACT FROM AUTHOR] more...

Prolificacy (the potential to produce ear shoots at multiple nodes on the main stalk) has been under selection since the early domestication of maize (Zea mays subsp. snays) from teosinte (Z. mays subsp. parviglumis). Until the early part of the 20th century, before mechanization, human selection may have favored single-eared maize because it facilitated hand-harvesting. Prolificacy, however, has the potential to increase stress tolerance under intensive management. Our objectives were (i) to assess variation for prolificacy and 15 related morphological traits in a population of 194 F3 families derived from inbred line A679 and a highly prolific S1 plant from the cultivar Golden Glow after 23 cycles of mass selection for prolificacy; and (ii) to determine relationships among traits and to infer which ones appear to be controlled by similar genetic factors. Traits were evaluated with two replications in three field environments. The population varied significantly for all traits and most traits had relatively high heritabilities (>0.80). Some traits were highly correlated, and two main groups were identified. These groups involved traits mostly associated with either the activity of axillary meristems, or intercalary meristems. In general, the correlations of traits across these two groups were insignificant or of lesser magnitude than within groups, suggesting that common genetic factors might be influencing some of these morphological traits. [ABSTRACT FROM AUTHOR] more...

The open-pollinated maize (Zea mays subsp. mays) population Golden Glow [GG(MP)] provides excellent material for the study of morphological and genetic changes associated with selection for prolificacy. Late generations of the GG(MP), when planted at low densities, resemble the architecture of teosinte (Z. mays subsp. parviglumis), the ancestor of maize. Our objectives were (i) to identify molecular markers linked to chromosomal regions that influenced prolificacy and related morphological traits, (ii) to determine whether genes previously shown to influence branching patterns in maize were associated with quantitative trait loci (QTLs) influencing these traits, and (iii) to determine whether epistatic interactions among putative QTLs influenced prolificacy and correlated traits. A mapping population was developed from the cross of inbred A679 and a highly prolific S1 plant from Cycle 23 of GG(MP). Simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers were combined for the linkage map construction. Thirty-three QTLs were found for 14 of the 16 traits analyzed. A region located on Linkage Group 1 (LG 1) shared similarities with the pattern of development suggested for the teosinte branchedi (thi) mutant. This suggests that genetic control of prolificacy and associated traits in GG(MP) may resemble the genetic changes underlying branching morphology that occurred during maize domestication. No evidence for additive-by-additive epistatic interactions was found. [ABSTRACT FROM AUTHOR] more...

Examines the effectiveness of mass selection on increasing the number of active ear shoots of golden glow maize population. Evaluation on associated changes in ear and plant morphology after 24 cycles; Increase in the development of favorable genes without drastic loss of genetic variation; Relation between ear per plant increase and meristematic tissue activation. more...