Processes underlying the nutritional programming of embryonic development by iron deficiency in the rat

Peer reviewedPublisher PD

Geometrical Finiteness, Holography, and the BTZ Black Hole

We show how a theorem of Sullivan provides a precise mathematical statement of a 3d holographic principle, that is, the hyperbolic structure of a certain class of 3d manifolds is completely determined in terms of the corresponding Teichmuller space of the boundary. We explore the consequences of this theorem in the context of the Euclidean BTZ black hole in three dimensions.Comment: 6 pages, Latex, Version to appear in Physical Review Letter

Effects of Altering Supplementation Frequency During the Pre-Partum Period of Beef Cows Grazing Dormant Native Range

Spring-calving beef cattle that are grazing low-quality (\u3c 7% crude protein) dormant forage typically are unable to meet their maintenance requirements for protein. Providing a protein supplement (\u3e 30% crude protein) is recommended to decrease losses of body weight and body condition. Nutrient supplementation when forage quality is poor or limited is one of the largest expenditures for forage-based beef cattle operations. The expansion of the ethanol industry has afforded many producers in corn and sorghum-producing regions an alternative to traditional oilseed-based protein supplements. The availability and nutrient profile of distiller’s grains with solubles (DDG) has made it popular as a supplement for cows that are grazing dormant lowquality forages. Decreasing supplementation frequency reduces costs for labor and fuel. Previous research has shown no difference in body weights or body condition scores of cows supplemented with distiller’s grains daily, once every three days, or once every six days; however, the proportion of cows that ate hay during the 60 minutes immediately after supplementation was less on the day of supplementation for cows supplemented once every six days compared to cows supplemented daily. The observed decrease in hay consumption following supplementation could potentially decrease total organic matter intake during late gestation. More frequent supplementation may increase organic matter intake and improve performance during the month before parturition. Therefore, the objective of this study was to evaluate effects of altering frequency of supplementing distiller’s grains during the last 28 days of gestation with respect to performance of spring-calving beef cows consuming low-quality dormant native range

Performance of Beef Replacement Heifers Supplemented With Dried Distillers Grains With Solubles Versus a Mixture of Soybean Meal and Finely Ground Sorghum Grain

Costs of feed, labor, and equipment to develop heifers in a traditional confined feeding system are relatively high. Producers can greatly reduce input costs by developing heifers on dormant native range; however, heifers are unable to consume sufficient protein from the forage base. Suboptimal protein intake will reduce forage digestion and result in poor performance. Supplemental protein is required during these times to increase forage intake and digestion. The most efficient way of providing supplemental protein to heifers consuming lowquality (\u3c7% crude protein) forage is by feeding high-protein supplements (\u3e30% crude protein). Producers traditionally have used high-quality oilseed meals to supplement the necessary protein, but expansion of the ethanol industry has made dried distillers grains with solubles (DDGS) a potentially less expensive supplement option for producers in corn- and sorghum-producing areas. The objective of this study was to evaluate the effects of daily supplementation of DDGS vs. a mixture of soybean meal and finely ground sorghum grain on performance of replacement heifers grazing low-quality dormant native range

Performance of Beef Replacement Heifers Supplemented with Dried Distillers Grains or a Mixture of Soybean Meal and Ground Sorghum Grain

The feed, labor, and equipment costs of developing heifers in a confined feeding system are relatively high. High Plains beef producers can reduce input costs by developing heifers on dormant native range; however, heifers are typically unable to consume sufficient crude protein (CP) from the low-quality (\u3c 7% CP) forage base. Insufficient dietary protein reduces forage digestion and performance potential of growing heifers. Supplementing protein when forage quality was poor has previously been reported to increase forage intake and forage digestibility, which resulted in acceptable levels of performance. An efficient means of supplying supplemental protein to heifers consuming low-quality forage is through the use of supplements with relatively high crude protein concentrations (\u3e 30% CP). Traditionally, producers have used oilseed meals in this capacity, but with the expansion of the ethanol industry, dried distillers grains with solubles (DDG) have become widely available as an alternative protein source for producers in corn and sorghum-producing regions. Adequate heifer body weight and body condition score at first breeding are essential to minimize age at first calving and to increase lifetime productivity. Therefore, the objective of our study was to evaluate the effects of supplementation of DDG or an approximately isonitrogenous mixture of soybean meal and ground sorghum grain on growth and reproductive performance of replacement heifers grazing low-quality, dormant native range

Effects of Altering Supplementation Frequency During the Pre-Partum Period of Beef Cows Grazing Dormant Native Range

Spring-calving beef cattle that are grazing low-quality (\u3c 7% crude protein) dormant forage typically are unable to meet their maintenance requirements for protein. Providing a protein supplement (\u3e 30% crude protein) is recommended to decrease losses of body weight and body condition. Nutrient supplementation when forage quality is poor or limited is one of the largest expenditures for forage-based beef cattle operations. The expansion of the ethanol industry has afforded many producers in corn and sorghum-producing regions an alternative to traditional oilseed-based protein supplements. The availability and nutrient profile of distiller’s grains with solubles (DDG) has made it popular as a supplement for cows that are grazing dormant low-quality forages. Decreasing supplementation frequency reduces costs for labor and fuel. Previous research has shown no difference in body weights or body condition scores of cows supplemented with distiller’s grains daily, once every three days, or once every six days; however, the proportion of cows that ate hay during the 60 minutes immediately after supplementation was less on the day of supplementation for cows supplemented once every six days compared to cows supplemented daily. The observed decrease in hay consumption following supplementation could potentially decrease total organic matter intake during late gestation. More frequent supplementation may increase organic matter intake and improve performance during the month before parturition. Therefore, the objective of this study was to evaluate effects of altering frequency of supplementing distiller’s grains during the last 28 days of gestation with respect to performance of spring-calving beef cows consuming low-quality dormant native range

Non-uniqueness of ergodic measures with full Hausdorff dimension on a Gatzouras-Lalley carpet

In this note, we show that on certain Gatzouras-Lalley carpet, there exist more than one ergodic measures with full Hausdorff dimension. This gives a negative answer to a conjecture of Gatzouras and Peres

Involving users in OPAC interface design: Perspective from a UK study

This is the post-print versoin of the Article. The official published version can be accessed from the link below - Copyright @ 2007 SpringerThe purpose of this study was to determine user suggestions for a typical OPAC (Online Public Library Catalogue) application’s functionality and features. An experiment was undertaken to find out the type of interactions features that users prefer to have in an OPAC. The study revealed that regardless of users’ Information Technology (IT) backgrounds, their functionality expectations of OPACs are the same. However, based on users’ previous experiences with OPACs, their requirements with respect to specific features may change. Users should be involved early in the OPAC development cycle process in order to ensure usable and functional interface

Gott Time Machines, BTZ Black Hole Formation, and Choptuik Scaling

We study the formation of BTZ black holes by the collision of point particles. It is shown that the Gott time machine, originally constructed for the case of vanishing cosmological constant, provides a precise mechanism for black hole formation. As a result, one obtains an exact analytic understanding of the Choptuik scaling.Comment: 6 pages, Late

The effect of feeding a low iron diet prior to and during gestation on fetal and maternal iron homeostasis in two strains of rat

Background Iron deficiency anaemia during pregnancy is a global problem, with short and long term consequences for maternal and child health. Animal models have demonstrated that the developing fetus is vulnerable to maternal iron restriction, impacting on postnatal metabolic and blood pressure regulation. Whilst long-term outcomes are similar across different models, the commonality in mechanistic events across models is unknown. This study examined the impact of iron deficiency on maternal and fetal iron homeostasis in two strains of rat. Methods Wistar (n=20) and Rowett Hooded Lister (RHL, n=19) rats were fed a control or low iron diet for 4 weeks prior to and during pregnancy. Tissues were collected at day 21 of gestation for analysis of iron content and mRNA/protein expression of regulatory proteins and transporters. Results A reduction in maternal liver iron content in response to the low iron diet was associated with upregulation of transferrin receptor expression and a reduction in hepcidin expression in the liver of both strains, which would be expected to promote increased iron absorption across the gut and increased turnover of iron in the liver. Placental expression of transferrin and DMT1+IRE were also upregulated, indicating adaptive responses to ensure availability of iron to the fetus. There were considerable differences in hepatic maternal and fetal iron content between strains. The higher quantity of iron present in livers from Wistar rats was not explained by differences in expression of intestinal iron transporters, and may instead reflect greater materno-fetal transfer in RHL rats as indicated by increased expression of placental iron transporters in this strain. Conclusions Our findings demonstrate substantial differences in iron homeostasis between two strains of rat during pregnancy, with variable impact of iron deficiency on the fetus. Whilst common developmental processes and pathways have been observed across different models of nutrient restriction during pregnancy, this study demonstrates differences in maternal adaptation which may impact on the trajectory of the programmed response