Influence of fluid intake on endurance running performance A comparison between water, glucose and fructose solutions

The aim of the present study was to compare the influence of drinking water, a carbohydrate-electrolyte solution, containing additional free glucose (Glucose) or the same carbohydrate-electrolyte solution containing additional fructose (Fructose), on running performance. Twelve endurance-trained recreational runners volunteered to take part in this study; 9 completed the three and all 12 completed two trials. The subjects were randomly assigned to one of the three trials: Water, Glucose or Fructose. In each trial the subjects were required to run 30 km as fast as possible on a motorized treadmill, instrumented so that they could control its speed. The carbohydrate-electrolyte solutions contained a total of 50 g carbohydrate, 20 g as a glucose polymer. The Glucose solution contained an additional 20 g free glucose and the Fructose solution contained an additional 20 g fructose rather than glucose. The osmolality of the Glucose and Fructose solutions was approximately 300-320 mosmol and the energy equivalent of both solutions was 794 kJ.l-1. The subjects ingested 1 l fluid throughout each run. The running times were not significantly different, being 129.3 (+/- 17.7) min, 124.8 (+/- 14.9) min and 125.9 (+/- 17.9) min for Water, Glucose and Fructose respectively. There was a decrease (P less than 0.05) in running speed over the last 10 km of the Water trial from 4.14 (+/- 0.55) to 3.75 (+/- 0.86) m.s-1, which did not occur in the carbohydrate trials. Blood glucose concentrations during the Water trial decreased from 15 km onwards and at the end of the run they were significantly (P less than 0.05) lower than the value recorded at 15 km.(ABSTRACT TRUNCATED AT 250 WORDS)     

De novo mutations producing unstable hemoglobins or hemoglobins M

Summary Hemoglobins M and unstable hemoglobins cause clinical syndromes that are transmitted in autosomal dominant fashion. Pedigrees of 50 probands with de novo mutations producing unstable Hb disease or Hb M disease were compiled. Cases were ascertained (1) by screening the relevant literature published from 1950 through 1980 and (2) through personal communication. Additional pedigree data on several published cases were collected, and a depository containing all available information rekated to de novo Hb mutants was established. The 50 probands were born in 14 countries between 1922 and 1976. Paternity was tested in 36% of the cases, and no instance of false paternity was noted.The data were used to test for an association of advanced parental age with the appearance of de novo mutants. Paternal ages at the probands' births ranged from 20 to 50 years, with a mean of 32.7 years. Maternal ages ranged from 18 to 43 years, with a mean of 28.5 years. For each year and country (or, where necessary, for the nearest possible year and/or a demographically similar country), the cumulative frequency distributions of the ages of parents who had a child in that country and year were computed; the ages of each proband's father and mother were then expressed as percentiles on these distributions. The distribution of paternal age percentiles was shifted toward the upper end of the range, with 11 of the 50 paternal ages falling between the 90th and 100th percentiles. The distribution of maternal age percentiles was more complex, with one peak (10 of 50 ages) falling between the 30th and 40th percentiles and a second peak (10 of 50 ages), between the 90th and 100th percentiles. These distributions, though suggestive of an association of advanced parental age and the appearance of de novo mutations that cause unstable Hb disease or methemoglobinemic cyanosis, were not significantly different from those uniform distributions expected in the absence of a parental age effect.     

Fetal hemoglobin of the rhesus monkey, Macaca mulatta: complete primary structure of the gamma chain

The complete amino acid sequence of the gamma chain from the major one of two fetal hemoglobins from the rhesus monkey, Macaca mulatta, was determined by automated, stepwise degradation of selected fragments produced by cleavage at methionyl and tryptophanyl residues and at the single aspartylprolyl bond. The minor fetal hemoglobin is single aspartylprolyl bond. The minor fetal hemoglobin is similar to human Hb F1 in relative electrophoretic and chromatographic properties and in the level at which it is found (about 12% of the total Hb F). On these grounds, we assume that this minor component contains, like Hb FI, gamma chains that differ from those of the major component by virtue of acetylation of their amino-terminal glycyl residues. Although the gamma chains of most antropoid primates examined to date are structurally heterogeneous and, hence, appear to be encoded by nonallelic genes, no sign of structural heterogeneity was detected at any position in the major gamma chain from M. mulatta. Thus, if nonallelic gamma-chain genes exist in this species, the chains encoded by them may be identical in sequence. The gamma chain from M. mulatta is but the sixth primate gamma chain whose primary structure has been fully characteerized. The slight extent of structural divergence among these chains (the four chains from various species of Old World monkeys differ from one another by no more than two substitutions, while the human and cercopithecoid gamma chains differ at no more than five sites) attests to the conservative nature of gamma-chain evolution among the higher primates.     

Fetal hemoglobin in newborn baboons, Papio cynocephalus

Hemoglobins from a newborn baboon, Papio cynocephalus, and from a 15-day-old baboon of the same species were examined for electrophoretic properties of polypeptide chains and were tested for alkali resistance. Hemoglobin of newborn P. cynocephalus appears to be analogous to human fetal hemoglobin. Hemoglobin of newborn P. cynocephalus is composed of α-like and γ-like chains and hemoglobin of adult P. cynocephalus is composed of α-like and β-like chains.     

Hemogloblin α-gene duplication in macaques: Individual Macaca nemestrina with three structurally different α chains

The diversity of hemoglobin phenotypes observed among Malaysian Macaca nemestrina (pig-tailed macaques) has been attributed, in part, to the presence of duplicated α-chain loci in some members of this species. To date, evidence in support of this view has been indirect, consisting of variation in proportions of α^I (Asp₇₁, Gln₇₈) and α^II (Asp₇₁, His₇₈) chains among presumptive heterozygotes. However, the discovery that erythrocytes from some M. nemestrina contain α^I and α^II chains in company with a third, or α^III, chain (Gly₇₁, Gln₇₈) provides direct evidence of duplicated α-chain loci.     

Scaling statistical multiple sequence alignment to large datasets

Background

Multiple sequence alignment is an important task in bioinformatics, and alignments of large datasets containing hundreds or thousands of sequences are increasingly of interest. While many alignment methods exist, the most accurate alignments are likely to be based on stochastic models where sequences evolve down a tree with substitutions, insertions, and deletions. While some methods have been developed to estimate alignments under these stochastic models, only the Bayesian method BAli-Phy has been able to run on even moderately large datasets, containing 100 or so sequences. A technique to extend BAli-Phy to enable alignments of thousands of sequences could potentially improve alignment and phylogenetic tree accuracy on large-scale data beyond the best-known methods today.

Results

We use simulated data with up to 10,000 sequences representing a variety of model conditions, including some that are significantly divergent from the statistical models used in BAli-Phy and elsewhere. We give a method for incorporating BAli-Phy into PASTA and UPP, two strategies for enabling alignment methods to scale to large datasets, and give alignment and tree accuracy results measured against the ground truth from simulations. Comparable results are also given for other methods capable of aligning this many sequences.

Conclusions

Extensions of BAli-Phy using PASTA and UPP produce significantly more accurate alignments and phylogenetic trees than the current leading methods.