Relation between endurance time and maximal oxygen consumption during supramaximal running

The relationship between speed and the maximal length of time supramaximal runs can be sustained (temps-limite, tlim) has been studied in seven male subjects (physical education students). Within the range of intensity studied, tlim strictly depends on maximal oxygen consumption (VO2max). The relationship between tlim and the relative energy cost of the exercises per unit of time (E), calculated by subtracting the maximal power of aerobic metabolism (Emaxox) from E, removes the interindividual differences of tlim. The function tlim = f(E-Emaxox) is described by an empirical equation of the form: tlim = a.exp[-b(E-Emaxox)] (r = 0.979; P less than 0.001), where the parameters a and b are respectively equal to 330.8 and 0.14 and where tlim, E and Emaxox are respectively expressed in seconds and in watts per kg of body weight.     

Age and sex composition of small ruminants at Nouakchott markets, Mauritania

A survey of species, breeds, sex and age composition of sheep and goats offered for sale was made at Nouakchott (Mauritania) livestock markets. Some 82.8% of animals presented at the markets were sheep and 95% of these were of the Short-haired Maure breed, the remainder being Long-haired Maure. Goats of the Sahel breed comprised 81% of all animals of this species, the others being Sahara and Eastern Dwarf types, but goats represented only 17.2% of all animals brought to market. Castrated Short-haired Maure sheep were 63.6% of this breed whereas castrates of Long-haired Maure sheep were 40.6% of the total. There were significantly more castrates than entire males presented for sale for sheep but the reverse was the case for goats. Entire males of both species were sold at younger ages than castrates and males and castrates combined were sold at younger ages than females. This study has provided some indications of the types of stock offered for sale but further studies at peak sale times would allow more detailed analysis. Such an analysis should be coupled with a survey of owners/herders and of traders in order to determine the factors operating on market forces.     

Cardiovascular changes induced by isometric exercise in aged subjects

Blood pressure and heart rate during static contraction of forearm muscles holding a tension of 30% maximal voluntary strength for 5 mn have been measured. Eleven young men and 11 elderly male subjects were used. Maximal voluntary strength is reduced by 19% in elderly subjects. Relative mean cardio-vascular responses were unaffected by age.     

Electric activity of the rectus femoris in supramaximal running

The electrical activity of the rectus femoris has been analysed in nine subjects during the course of a supramaximal run performed until exhaustion. The integrated electromyogram and the median frequency do not change significantly as a function of time.     

Low dose insemination in cattle with the Ghent device

A new artificial insemination device for semen deposition near the uterotubal junction (UTJ) in cattle (Ghent device) was developed at Ghent University (Belgium). In this study, UTJ insemination of dairy cows with the Ghent device was compared with the conventional insemination technique to evaluate the effect on pregnancy rates after insemination with different doses of semen. In each of three field trials, the cows (n=795, 659, 360) and heifers (n=253, 182, 231) were randomly assigned to receive 12 million sperm deposited in the uterine body using conventional techniques (control) or a reduced sperm dose (RSD) deposited in the same manner as the control or bilateral deposition near the uterotubal junction using the Ghent device (Ghent). Sperm dosages for RSD and Ghent inseminations were 8, 4, and 2 million sperm for field trials 1-3, respectively. In the multivariable analysis, the pregnancy rates were significantly affected by the parity of the cow (p相似文献   

Structural features in the KshA terminal oxygenase protein that determine substrate preference of 3-ketosteroid 9α-hydroxylase enzymes

Rieske nonheme monooxygenase 3-ketosteroid 9α-hydroxylase (KSH) enzymes play a central role in bacterial steroid catabolism. KSH is a two-component iron-sulfur-containing enzyme, with KshA representing the terminal oxygenase component and KshB the reductase component. We previously reported that the KshA1 and KshA5 homologues of Rhodococcus rhodochrous DSM43269 have clearly different substrate preferences. KshA protein sequence alignments and three-dimensional crystal structure information for KshA(H37Rv) of Mycobacterium tuberculosis H37Rv served to identify a variable region of 58 amino acids organized in a β sheet that is part of the so-called helix-grip fold of the predicted KshA substrate binding pocket. Exchange of the β sheets between KshA1 and KshA5 resulted in active chimeric enzymes with substrate preferences clearly resembling those of the donor enzymes. Exchange of smaller parts of the KshA1 and KshA5 β-sheet regions revealed that a highly variable loop region located at the entrance of the active site strongly contributes to KSH substrate preference. This loop region may be subject to conformational changes, thereby affecting binding of different substrates in the active site. This study provides novel insights into KshA structure-function relationships and shows that KSH monooxygenase enzymes are amenable to protein engineering for the development of biocatalysts with improved substrate specificities.     

A new locus for otosclerosis, OTSC8, maps to the pericentromeric region of chromosome 9

Otosclerosis is a common disorder of the otic capsule resulting in hearing impairment in 0.3–0.4% of the Caucasian population. The aetiology of the disease remains unclear. In most cases, otosclerosis can be considered as a complex disease. In some cases, the disease is inherited as an autosomal dominant trait, sometimes with reduced penetrance. To date, seven autosomal dominant loci have been reported, but none of the disease-causing genes has been identified. In this study, we present the results of a genome-wide linkage analysis in a large Tunisian family segregating autosomal dominant otosclerosis. Linkage analysis localised the responsible gene to chromosome 9p13.1-9q21.11 with a maximal LOD score of 4.13, and this locus was named OTSC8. Using newly generated short tandem repeat polymorphism markers, we mapped this new otosclerosis locus to a 34.16 Mb interval between the markers D9S970 and D9S1799. This region comprises the pericentromeric region on both arms of chromosome 9, a highly complex region containing many duplicated sequences. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Single Nucleotide Polymorphism Genotyping and Distribution of Coxiella burnetii Strains from Field Samples in Belgium

The genotypic characterization of Coxiella burnetii provides useful information about the strains circulating at the farm, region, or country level and may be used to identify the source of infection for animals and humans. The aim of the present study was to investigate the strains of C. burnetii circulating in caprine and bovine Belgian farms using a single nucleotide polymorphism (SNP) technique. Direct genotyping was applied to different samples (bulk tank milk, individual milk, vaginal swab, fetal product, and air sample). Besides the well-known SNP genotypes, unreported ones were found in bovine and caprine samples, increasing the variability of the strains found in the two species in Belgium. Moreover, multiple genotypes were detected contemporarily in caprine farms at different years of sampling and by using different samples. Interestingly, certain SNP genotypes were detected in both bovine and caprine samples, raising the question of interspecies transmission of the pathogen.