A comparison of anthropometric and training characteristics among recreational male ironman triathletes and ultra-endurance cyclists

"The physique of Ironman triathletes was considered to be similar to that of cyclists. We intended to investigate differences and similarities in anthropometry and training between 83 Ironman triathletes competing in a qualifier for 'Ironman Hawaii' and 84 ultra-endurance cyclists competing in a qualifier for the 'Race across America'. The anthropometric and training characteristics were compared between these two groups of athletes; associations of anthropometric and training characteristics with race time were investigated using bi- and multi-variate analysis. The Ironman triathletes had shorter legs, lower circumferences of upper arm, thigh and calf and a lower skeletal muscle mass compared to the ultra- cyclists. The Ironman triathletes invested more weekly training hours but fewer weekly cycling hours than the ultra-cyclists; the ultra-cyclists completed more cycling kilometres per week. In the multi- variate analysis, the skin-fold thicknesses at abdominal (P = 0.02) and iliacal site (P = 0.02) as well as percent body fat (P = 0.0008) were associated with race time for the Ironman triathletes. The abdominal (P = 0.003) and the iliacal (P = 0.02) skin-fold thicknesses, percent body fat (P = 0.001) and cycling speed during training (P = 0.01) were related to cycling split time in the Ironman race. For the ultra-cyclists, percent body fat (P = 0.04) was related to race time. We concluded that anthropometry and training of Ironman triathletes were different when compared to ultra-endurance cyclists."     

No case of exercise-associated hyponatremia in male ultra-endurance mountain bikers in the 'Swiss Bike Masters'

Exercise-associated hyponatremia (EAH) has mainly been investigated in runners and triathletes. In mountain bikers, EAH was studied in two multi-stage races, but not in a single stage race. The aim of this study was to investigate the prevalence of EAH in a single-stage mountain bike ultra-marathon. In the 'Swiss Bike Masters' over 120 km with a climb of ~ 5,000 m in altitude, we determined pre and post race body mass, hematocrit, plasma sodium concentration ([Na?]), and urinary specific gravity in 37 cyclists. Athletes recorded their fluid intake while racing. No athlete developed EAH. The cyclists drank on average (means ± SD) 0.7 ± 0.2 l/h. Fluid intake was significantly and negatively related to race time (r = -0.41, P < 0.05), but showed no association with post race plasma [Na?], the change in plasma [Na?], post race body mass, or the change in body mass. The athletes lost 1.4 kg body mass (P < 0.05), plasma [Na?] decreased by 0.7% (P < 0.05), plasma volume increased by 1.4% and urinary specific gravity increased by 0.4% (P < 0.05). The change in body mass was neither related to post race plasma [Na?] nor to the change in plasma [Na?]. The decrease in plasma [Na?] was not related to fluid intake. The change in plasma [Na?] was related to post race plasma [Na?] (r = 0.40, P < 0.01). Ad libitum fluid intake showed no case of EAH in a single-stage mountain bike ultra-marathon. In contrast to previous findings, the faster athletes drank more than the slower ones.     

"Personal best times in an olympic distance triathlon and a marathon predict an ironman race time for recreational female triathletes"

"The aim of this study was to investigate whether the characteristics of anthropometry, training or previous performance were related to an Ironman race time in recreational female Ironman triathletes. These characteristics were correlated to an Ironman race time for 53 recreational female triathletes in order to determine the predictor variables, and so be able to predict an Ironman race time for future novice triathletes. In the bi-variate analysis, no anthropometric characteristic was related to race time. The weekly cycling kilometers (r = -0.35) and hours (r = -0.32), as well as the personal best time in an Olympic distance triathlon (r = 0.49) and in a marathon (r = 0.74) were related to an Ironman race time (< 0.05). Stepwise multiple regressions showed that both the personal best time in an Olympic distance triathlon ( P = 0.0453) and in a marathon (P = 0.0030) were the best predictors for the Ironman race time (n = 28, r2 = 0.53). The race time in an Ironman triathlon might be partially predicted by the following equation (r2 = 0.53, n = 28): Race time (min) = 186.3 + 1.595 × (personal best time in an Olympic distance triathlon, min) + 1.318 × (personal best time in a marathon, min) for recreational female Ironman triathletes."     

Higher prevalence of Alternaria spp. in marine and river waters than in potable samples

Alternaria species have been recognized as important cause of allergic diseases and are considered opportunistic pathogens for immunocompromised individuals. In order to assess the contribution of waters to the spread of Alternaria, we examined 390 water samples of various origin for the presence of these microorganisms in parallel with the standard pollution indicator bacteria, i.e. total coliforms, faecal coliforms and enterococci. Alternaria spp. were isolated from 42 out of 196 (21.4%) marine water samples, from 13 out of 68 (19.1%) river samples, whereas out of 126 potable waters only two (1.6%) were found positive. The incidence of Alternaria was significantly higher (p < 0.001) in marine and river samples than in potable waters. The mean values of the colony-forming units of the pollution indicator bacteria did not significantly differ between Alternaria-positive and Alternaria-negative samples.     

Higher permeability for water than for ethyl alcohol in Nitella

If we apply water at one end of a Nitella cell, A, and place at the other end, B, a solution of a substance which does not penetrate, such as sucrose, water enters the cell at A, passes along inside the cell, and escapes at B. But if in place of sucrose we use a substance which penetrates such as ethyl alcohol the flow of water is lessened and this fact makes it possible to measure the amount of alcohol which enters. (An increase in the size of cells placed in solutions of alcohol does not necessarily indicate that the number of mols of alcohol entering is greater than the number of mols of water leaving the cell.) The permeability for water is more than 18 times as great as for ethyl alcohol. The behavior of the 2 substances was compared in the same individual cell with a driving force which at the start was the same for both substances. The number of mols entering per second per cm.² of surface with a driving force of 1 atmosphere at 25°C. is 0.772 (10^–6) for water and 0.042 (10^–6) for ethyl alcohol. The experiments indicate that the non-aqueous substance at the surface of the protoplasm has a higher partition coefficient for water than for ethyl alcohol, although the protoplasmic surface is composed of materials not miscible with water.     

Pi MZ phenotype and an increased prevalence of reported psoriasis in a community survey

In a community survey of 953 adults we identified 40 who reported having had psoriasis. Eight of these cases were subsequently documented from physicians' records. alpha 1-Antitrypsin (alpha 1-AT) phenotyping identified 35 MZ individuals, 4 (11.4%) of whom reported psoriasis. Among the 918 non-MZ individuals 36 (3.9%) reported psoriasis, yielding a relative incidence of 3.2 (p less than 0.05). This is consistent with previous reports suggesting an association between moderate alpha 1-AT deficiency and psoriasis.     

Rabies prevalence in migratory tree-bats in Alberta and the influence of roosting ecology and sampling method on reported prevalence of rabies in bats

The migratory tree-roosting hoary bat (Lasiurus cinereus) and silver-haired bat (Lasionycteris noctivagans) are among the bat species with the highest reported prevalence of rabies in North America. However, bats submitted for rabies testing typically have been those that have come in contact with humans or pets. Given the roosting ecology of L. cinereus and L. noctivagans, contact with healthy individuals of these species is expected to be rare, with a bias in contact and submission of infected individuals and thus an overestimation of rabies prevalence. We tested 121 L. cinereus and 96 L. noctivagans specimens, collected during mortality surveys at wind energy facilities in Southern Alberta, Canada in 2007 and 2008, for rabies. None of the L. cinereus (0%) and one L. noctivagans (1%) tested positive for rabies. Prevalence of rabies was significantly lower than previously reported estimates, passive and active, for L. cinereus and L. noctivagans. In a review of the literature including multiple bat species, we found a significant difference in estimates of rabies prevalence based on passive versus active surveillance testing. Furthermore, roosting ecology influenced estimates of rabies prevalence, with significantly higher prevalence among passive surveillance submissions of nonsynanthropic species compared to synanthropic species, a trend not evident in active surveillance reports. We conclude that rabies prevalence in randomly collected L. cinereus and L. noctivagans is low and comparable to active surveillance estimates from other species (≤ 1%), and that roosting ecology influences estimates of rabies prevalence among bats submitted to public health laboratories in North America.     

Higher masseter muscle mass in grazing than in browsing ruminants

Using cranioskeletal measurements, several studies have generated evidence that grazing ruminants have a more pronounced mastication apparatus, in terms of muscle insertion areas and protuberances, than browsing ruminants, with the resulting hypothesis that grazers should have larger, heavier chewing muscles than browsers. However, the only investigation of this so far [Axmacher and Hofmann (J Zool 215:463-473, 1988)] did not find differences between ruminant feeding types in the masseter muscle mass of 22 species. Here, we expand the dataset to 48 ruminant species. Regardless of phylogenetic control in the statistical treatment, there was a significant positive correlation of body mass and masseter mass, and also a significant association between percent grass in the natural diet and masseter mass. The results support the concept that ruminant species that ingest more grass have relatively larger masseter muscles, possibly indicating an increased requirement to overcome the resistance of grass forage. The comparative chewing resistance of different forage classes may represent a rewarding field of ecophysiological research.     

Year-round prevalence of norovirus in the environment of catering companies without a recently reported outbreak of gastroenteritis

Food handlers play an important role in the transmission of norovirus (NoV) in food-borne outbreaks of gastroenteritis (GE). In a year-round prevalence study, the prevalence of NoV in catering companies without recently reported outbreaks of GE was investigated and compared to the observed prevalence in catering companies with recently reported outbreaks. Swab samples were collected from surfaces in the kitchens and (staff) bathrooms in 832 randomly chosen companies and analyzed for the presence of NoV RNA. In total, 42 (1.7%) out of 2,496 environmental swabs from 35 (4.2%) catering companies tested positive. In contrast, NoV was detected in 147 (39.7%) of the 370 samples for 44 (61.1%) of the 72 establishments associated with outbreaks of gastroenteritis. NoV-positive swabs were more frequently found in winter, in specific types of companies (elderly homes and lunchrooms), and in establishments with separate bathrooms for staff. We found a borderline association with population density but no relation to the number of employees. Sequence analysis showed that environmental strains were interspersed with strains found in outbreaks of illness in humans. Thus, the presence of NoV in catering companies seemed to mirror the presence in the population but was strongly increased when associated with food-borne GE. Swabs may therefore serve as a valuable tool in outbreak investigations for the identification of the causative agent, although results should be interpreted with care, taking into account all other epidemiological data.     

Higher Abundance of Bacteria than of Viruses in Deep Mediterranean Sediments

The interactions between viral abundance and bacterial density, biomass, and production were investigated along a longitudinal transect consisting of nine deep-sea stations encompassing the entire Mediterranean basin. The numbers of viruses were very low (range, 3.6 × 10⁷ to 12.0 × 10⁷ viruses g⁻¹) and decreased eastward. The virus-to-bacterium ratio was always < 1.0, indicating that the deep-sea sediments of the Mediterranean Sea are the first example of a marine ecosystem not numerically dominated by viruses. The lowest virus numbers were found where the lowest bacterial metabolism and turnover rates and the largest cell size were observed, suggesting that bacterial doubling time might play an important role in benthic virus development.     

Higher abundance of bacteria than of viruses in deep Mediterranean sediments

The interactions between viral abundance and bacterial density, biomass, and production were investigated along a longitudinal transect consisting of nine deep-sea stations encompassing the entire Mediterranean basin. The numbers of viruses were very low (range, 3.6 x 10(7) to 12.0 x 10(7) viruses g(-1)) and decreased eastward. The virus-to-bacterium ratio was always < 1.0, indicating that the deep-sea sediments of the Mediterranean Sea are the first example of a marine ecosystem not numerically dominated by viruses. The lowest virus numbers were found where the lowest bacterial metabolism and turnover rates and the largest cell size were observed, suggesting that bacterial doubling time might play an important role in benthic virus development.     

Reduced exercise-associated response of the GH-IGF-I axis and catecholamines in obese children and adolescents.

Obesity blunts catecholamine and growth hormone (GH) responses to exercise in adults, but the effect of obesity on these exercise-associated hormonal responses in children is unclear. Therefore, the aim of the present study was to asses the effect of childhood obesity on the counterregulatory hormonal response to acute exercise. Twenty-five obese children (Ob; body mass index > 95%), and 25 age, gender, and maturity-matched normal-weight controls (NW) participated in the study. Exercise consisted of ten 2-min bouts of constant-cycle ergometry above the anaerobic threshold, with 1-min rest intervals between each bout. Pre-, post-, and 120-min postexercise blood samples were collected for circulating components of the GH-IGF-I axis and catecholamines. There were no differences in peak exercise heart rate, serum lactate, and peak O2 uptake normalized to lean body mass between the groups. Obesity attenuated the GH response to exercise (8.9 +/- 1.1 vs. 3.4 +/- 0.7 ng/ml in NW and Ob participants, respectively; P < 0.02). No significant differences in the response to exercise were found for other components of the GH-IGF-I axis. Obesity attenuated the catecholamine response to exercise (epinephrine: 52.5 +/- 12.7 vs. 18.7 +/- 3.7 pg/ml, P < 0.02; norepinephrine: 479.5 +/- 109.9 vs. 218.0 +/- 26.0 pg/ml, P < 0.04; dopamine: 17.2 +/- 2.9 vs. 3.5 +/- 1.9 pg/ml, P < 0.006 in NW and Ob, respectively). Insulin levels were significantly higher in the obese children and dropped significantly after exercise in both groups. Despite the elevated insulin levels and the blunted counterregulatory response, none of the participants developed hypoglycemia. Childhood obesity was associated with attenuated GH and catecholamine response to acute exercise. These abnormalities were compensated for, so that exercise was not associated with hypoglycemia, despite increased insulin levels in obese children.     

Evidence for increased prevalence of SRY mutations in XY females with complete rather than partial gonadal dysgenesis.

The Y chromosome gene SRY (sex-determining region, Y gene) has been equated with the mammalian testis-determining factor. The SRY gene of five subjects with 46,XY complete gonadal dysgenesis (46,XY karyotype, completely female external genitalia, normal Müllerian ducts, and streak gonads) was evaluated for possible mutations in the coding region by using both single-strand conformation polymorphism (SSCP) assay and DNA sequencing. Mutations were identified in three subjects, of which two gave altered SSCP patterns. Two of them were point mutations causing amino acid substitutions, and the third was a single-base deletion causing a frameshift. All three mutations caused alterations in the putative DNA-binding region of the SRY protein. Genomic DNA was obtained from the fathers of two of the three mutant patients: one mutation was demonstrated to be de novo, and the other was inherited. The presence of SRY mutations in three of five patients suggests that the frequency of SRY mutations in XY females is higher than current estimates.     

Higher rates of amino acid substitution in rodents than in humans.

An analysis of 54 protein sequences from humans and rodents (mice or rats), with the chicken as an outgroup, indicates that, from the common ancestor of primates and rodents, 35 of the proteins have evolved faster in the lineage to mouse or rat (rodent lineage) whereas only 12 proteins have evolved faster in the lineage to humans (human lineage). The average rate of amino acid substitution is significantly faster in the rodent lineage than in the human lineage. In addition, the average rate of insertion/deletion is also faster in rodents than in humans and there is a positive correlation between the rate of amino acid substitution and the rate of insertion/deletion in a protein sequence.     

Higher reproductive skew among birds than mammals in cooperatively breeding species

While competition for limited breeding positions is a common feature of group life, species vary widely in the extent to which reproduction is shared among females (‘reproductive skew’). In recent years, there has been considerable debate over the mechanisms that generate variation in reproductive skew, with most evidence suggesting that subordinates breed when dominants are unable to prevent them from doing so. Here, we suggest that viviparity reduces the ability of dominant females to control subordinate reproduction and that, as a result, dominant female birds are more able than their mammal counterparts to prevent subordinates from breeding. Empirical data support this assertion. This perspective may increase our understanding of how cooperative groups form and are stabilized in nature.     

Reduced Efficiency of Magnetotaxis in Magnetotactic Coccoid Bacteria in Higher than Geomagnetic Fields

Magnetotactic bacteria are microorganisms that orient and migrate along magnetic field lines. The classical model of polar magnetotaxis predicts that the field-parallel migration velocity of magnetotactic bacteria increases monotonically with the strength of an applied magnetic field. We here test this model experimentally on magnetotactic coccoid bacteria that swim along helical trajectories. It turns out that the contribution of the field-parallel migration velocity decreases with increasing field strength from 0.1 to 1.5 mT. This unexpected observation can be explained and reproduced in a mathematical model under the assumption that the magnetosome chain is inclined with respect to the flagellar propulsion axis. The magnetic disadvantage, however, becomes apparent only in stronger than geomagnetic fields, which suggests that magnetotaxis is optimized under geomagnetic field conditions. It is therefore not beneficial for these bacteria to increase their intracellular magnetic dipole moment beyond the value needed to overcome Brownian motion in geomagnetic field conditions.     

Higher risk of seizures in offspring of mothers than of fathers with epilepsy.

Seizure risk has consistently been found to be higher in offspring of mothers than of fathers with epilepsy. This pattern cannot be explained by any simple genetic model. The present study examined the possibility that the pattern arises from differences between affected mothers and fathers in the characteristics of their epilepsy that influence offspring seizure risk. The study population comprised 687 offspring of parents with epilepsy from the Rochester-Olmsted County Record Linkage Project. Cumulative incidences of unprovoked seizures to age 25 were 8.7% and 2.4% in offspring of affected mothers and fathers, respectively. Cox proportional hazards analysis was used to calculate rate ratios (RRs) for unprovoked seizures in offspring. In the univariate analysis, risk of unprovoked seizures was higher if the affected parent was the mother (RR = 2.8, 95% confidence interval [ci] 1.1-7.2) or if the parent's onset was before age 20 (RR = 2.5, 95% ci 1.1-5.9), but there was no effect on offspring risk of either parent's etiology (idiopathic vs. remote symptomatic) or parent's seizure type (generalized vs. partial). These findings were not substantially changed in the multivariate analysis. Thus, differences between affected mothers and fathers in these characteristics did not account for the higher risk in offspring of affected mothers. Anticonvulsant use during pregnancy was not associated with increased offspring seizure risk.(ABSTRACT TRUNCATED AT 250 WORDS)     

A robust,sensitive assay for genomic uracil determination by LC/MS/MS reveals lower levels than previously reported

Considerable progress has been made in understanding the origins of genomic uracil and its role in genome stability and host defense; however, the main question concerning the basal level of uracil in DNA remains disputed. Results from assays designed to quantify genomic uracil vary by almost three orders of magnitude. To address the issues leading to this inconsistency, we explored possible shortcomings with existing methods and developed a sensitive LC/MS/MS-based method for the absolute quantification of genomic 2′-deoxyuridine (dUrd). To this end, DNA was enzymatically hydrolyzed to 2′-deoxyribonucleosides and dUrd was purified in a preparative HPLC step and analyzed by LC/MS/MS. The standard curve was linear over four orders of magnitude with a quantification limit of 5 fmol dUrd. Control samples demonstrated high inter-experimental accuracy (94.3%) and precision (CV 9.7%). An alternative method that employed UNG2 to excise uracil from DNA for LC/MS/MS analysis gave similar results, but the intra-assay variability was significantly greater. We quantified genomic dUrd in Ung^+/+ and Ung^?/? mouse embryonic fibroblasts and human lymphoblastoid cell lines carrying UNG mutations. DNA-dUrd is 5-fold higher in Ung^?/? than in Ung^+/+ fibroblasts and 11-fold higher in UNG2 dysfunctional than in UNG2 functional lymphoblastoid cells. We report approximately 400–600 dUrd per human or murine genome in repair-proficient cells, which is lower than results using other methods and suggests that genomic uracil levels may have previously been overestimated.     

2-week triple therapy for Helicobacter pylori infection is better than 1-week in clinical practice: a large prospective single-center randomized study

BACKGROUND: Proton pump inhibitor (PPI)-based triple therapies are considered the standard regimens for Helicobacter pylori eradication, but the optimal duration of these regimens is still controversial. The aim of this study was to compare the efficacy of 1-week versus 2-week triple therapies in H. pylori-positive patients. MATERIALS AND METHODS: A total of 486 consecutive H. pylori-positive patients were randomized to receive omeprazole, 20 mg b.i.d., clarithromycin 500 mg b.i.d., and either amoxicillin 1 g b.i.d. or metronidazole 500 mg b.i.d. for 1 or 2 weeks. Upper gastrointestinal endoscopy and histology were performed at entry and 2 months after the end of therapy. H. pylori status was defined according to histology and urea breath test. RESULTS: At intention-to-treat analysis, 2-week therapy with omeprazole, amoxicillin, and clarithromycin achieved a significantly higher eradication rate than 1- or 2-week regimens with metronidazole (70% versus 52%, p = .003, versus 56%, p < .01) and the same therapy for 1-week (70% versus 57%, p = .05). At per-protocol analysis, 2-week therapy with omeprazole, amoxicillin, and clarithromycin showed a significantly higher eradication rate than 1-week of amoxicillin and metronidazole (77% versus 62%; p = .03) but no difference with 1-week same regimen (66%) or 2-week metronidazole and clarithromycin regimen (72%). Compliance and tolerability were good for all regimens. CONCLUSIONS: Two-week therapies, independently of antibiotic combination, lead to a significant increase of H. pylori eradication rate compared to 1-week therapies, with same compliance and tolerability, even if, taking account of low-eradication rates, one must question whether the triple therapy should still be used.     

Higher diversity of Rhizobium leguminosarum biovar viciae populations in arable soils than in grass soils

The bacterial genetic diversity after long-term arable cultivation was compared with that under permanent grassland using replicated paired contrasts. Pea-nodulating Rhizobium leguminosarum populations were sampled from pairs of arable and grass sites at four locations in Yorkshire, United Kingdom. Isolates were characterized using both chromosomal (16S-23S ribosomal DNA internal transcribed spacer PCR-restriction fragment length polymorphism) and plasmid (group-specific repC PCR amplification) markers. The diversities of chromosomal types, repC profiles, and combined genotypes were calculated using richness in types (adjusted to equal sample sizes by rarefaction), Shannon-Wiener index, and Simpson's index. The relative differences in diversity within each pair of sites were similar for all three diversity measures. Chromosomal types, repC profiles, and combined genotypes were each more diverse in arable soils than in grass soils at two of the four locations. The other comparisons showed no significant differences. We conclude that rhizobial diversity can be affected by differences between these two management regimens. Multiple regression analyses indicated that lower diversity was associated with high potential nitrogen and phosphate levels or with acidity.