If others jump to the queue front, how long I will wait?

Two models of a queue are proposed: a human queue and two lines of vehicles before a narrowing. In both models, a queuer tries to evaluate his waiting time, taking into account the delay caused by intruders who jump to the queue front. As the collected statistics of such events is very limited, the evaluation can give very long times. The results provide an example, when direct observations should be supplemented by an inference from the context.Comment: 4 pages, 3 figure

Polygenic Study of Endurance-Associated Genetic Markers NOS3 (Glu298Asp), BDKRB2 (-9/+9), UCP2 (Ala55Val), AMPD1 (Gln45Ter) and ACE (I/D) in Polish Male Half Marathoners

The purpose of this study was to investigate individually and in combination the association between the ACE (I/D), NOS3 (Glu298Asp), BDKRB2 (-9/+9), UCP2 (Ala55Val) and AMPD1 (Gln45Ter) variants with endurance performance in a large, performance-homogenous cohort of elite Polish half marathoners. The study group consisted of 180 elite half marathoners: 76 with time 100 minutes. DNA of the subjects was extracted from buccal cells donated by the runners and genotyping was carried out using an allelic discrimination assay with a C1000 Touch Thermal Cycler (Bio-Rad, Germany) instrument with TaqMan® probes (NOS3, UCP2, and AMPD1) and a T100™ Thermal Cycler (Bio-Rad, Germany) instrument (ACE and BDKRB2). We found that the UCP2 Ala55Val polymorphism was associated with running performance, with the subjects carrying the Val allele being overrepresented in the group of most successful runners (100 min group (84.2 vs. 55.8%; OR = 4.23, p 100 min group (73.7 vs. 51.9%; OR = 2.6, p = 0.0034). These data suggest that the likelihood of becoming an elite half marathoner partly depends on the carriage of a high number of endurance-related alleles

The aspects of sex, age and nationality in winter swimming performance

OBJECTIVE Winter swimming is a new sport discipline. Very little is known, however, about the sex differences, origin, participation and performance of the world's best winter swimmers. Therefore, the study aimed to investigate sex differences in performance and age. Furthermore, it should be determined which country has the fastest swimmers, the highest numbers of participants and the most successful age group athletes in winter swimming. SUBJECTS AND METHODS A total of 6,477 results from the 25 m events of the IWSA (International Winter Swimming Association) World Cups from 2016-2020 was collected from the official website of IWSA. Data were analyzed using a generalized linear model (GLM) with a gamma probability distribution and identity link function. The 25 m events were carried out in head-up breaststroke style, freestyle and butterfly. The nationalities were grouped into six groups, the five nationalities with the highest number of participants in the 25 m competitions and one group with the other nationalities. The mean time of 25 m races by sex and country of the total sample was compared. For the top 10 comparisons, the best ten athletes from the six groups were selected. The mean time of each top 10 groups was compared by sex and nationality. RESULTS Men were faster than women for all categories. Swimmers in age group 15-29 years were the fastest, where females were the fastest in age group 15-19 years and males in age group 20-29 years. Women from both Russia and Estonia and men from both Russia and China were the fastest. Both Russian and Chinese males were the fastest in all water categories in the top 10 section in the 25 m events. CONCLUSIONS In summary, males were faster than females in the IWSA World Cups between 2016 and 2020. The age group of 15-29 years old athletes was the most successful while females had their age of peak performance earlier than males. Russian and Estonian males and Russian females were the overall fastest in the 25 m events in all water categories. Future studies should investigate the optimal anthropometric characteristics of male and female winter swimming sprint athletes and whether there are distinct areas in Russia, Estonia and China, where many international winter swimming athletes originate

The NOS3 G894T (rs1799983) and-786T/C (rs2070744) polymorphisms are associated with elite swimmer status

Endothelial nitric oxide synthase (NOS3) generates nitric oxide in blood vessels and is involved in the regulation of vascular function, metabolism and muscle fibre type transformations. Evidence suggests that the NOS3 G894T (rs1799983) and -786T/C (rs2070744) polymorphisms are associated with athletic performance. The purpose of this study was to determine the association between the NOS3 G894T and -786T/C polymorphisms with elite swimmer status in Polish athletes. One hundred and ninety-seven Polish swimmers (104 males and 93 females), who competed in national and international events, and 379 healthy control subjects (222 males and 157 females) were recruited for this study. The swimmers were divided into two groups: short distance swimmers (SDS; n=147; 50-200 m) and long distance swimmers (LDS; n=49; more than 500 m). As expected, the frequencies of the -786T/C T allele (77.0 vs. 63.1%, p = 0.0085) and G-T haplotype (63.7 vs. 52.0, p=0.025) were significantly higher in the LDS group in comparison with controls. Compared with the -786T/C CC genotype, the chance of being a long distance swimmer was 8.49 times higher (CI=1.14-62.78, p=0.023) for the carriers of -786T/C T allele than in control subjects. On the other hand, the Asp allele frequency was significantly higher in the female SDS group compared with controls (34.3 vs. 18.5%, p=0.00043). In conclusion, our results demonstrate that the T allele and the G-T haplotype of the -786T/C and G894T polymorphisms may be beneficial for long distance swimmers

Physical activity characterization:Does one site fit all?

Background: It is evident that a growing number of studies advocate a wrist-worn accelerometer for the assessment of patterns of physical activity a priori, yet the veracity of this site rather than any other body-mounted location for its accuracy in classifying activity is hitherto unexplored. Objective: The objective of this review was to identify the relative accuracy with which physical activities can be classified according to accelerometer site and analytical technique. Methods: A search of electronic databases was conducted using Web of Science, PubMed and Google Scholar. This review included studies written in the English language, published between database inception and December 2017, which characterized physical activities using a single accelerometer and reported the accuracy of the technique. Results: A total of 118 articles were initially retrieved. After duplicates were removed and the remaining articles screened, 32 full-text articles were reviewed, resulting in the inclusion of 19 articles that met the eligibility criteria. Conclusion: There is no 'one site fits all' approach to the selection of accelerometer site location or analytical technique. Research design and focus should always inform the most suitable location of attachment, and should be driven by the type of activity being characterized

Molecular basis of malignant hyperthermia

Malignant hyperthermia (MH) is a clinical syndrome in which genetically susceptible individuals respond to the administration of potent inhalation anaesthetics and depolarization skeletal muscle relaxants with skeletal rigidity, unstable blood pressure, tachycardia, arrhythmias, hyperventilation, hypoxia, lactic and respiratory acidosis and high fever. In studies of the genetic basis of MH, a mutation was identified in the porcine (C1843T) and human (C1840T) skeletal muscle ryanodine receptor (RYR1) gene. This gene is mapped on human chromosome 19q13.1. The RYR1 gene contains 106 exons, of which two arc alternatively spliced