Drag of suction cup tags on swimming animals: Modeling and measurement

Bio‐logging tags are widely used to study the behavior and movements of marine mammals with the tacit assumption of little impact to the animal. However, tags on fast‐swimming animals generate substantial hydrodynamic forces potentially affecting behavior and energetics adversely, or promoting early removal of the tag. In this work, hydrodynamic loading of three novel tag housing designs are compared over a range of swimming speeds using computational fluid dynamics (CFD). Results from CFD simulation were verified using tag models in a water flume with close agreement. Drag forces were reduced by minimizing geometric disruptions to the flow around the housing, while lift forces were reduced by minimizing the frontal cross‐sectional area of the housing and holding the tag close to the attachment surface. Hydrodynamic tag design resulted in an experimentally measured 60% drag force reduction in 5.6 m/s flow. For all housing designs, off‐axis flow increased the magnitude of the force on the tag. Experimental work with a common dolphin (Delphinus delphis) cadaver indicates that the suction cups used to attach the types of tags described here provide sufficient attachment force to resist failure to predicted forces at swimming speeds of up to 10 m/s.     

Drag reduction of fish skin mucus: Relationship to mode of swimming and size

Drag reduction by skin mucus was measured from Gulf of Eilat fish. Activity of burst swimmers was greater than manoeuvre swimming fish. Large fish from the same species had higher mucus drag reducing activity than smaller specimens.     

Flow visualization of competitive swimming techniques: the tufts method

The purpose of this study was to evaluate the use of tufts to visualize the flow of water around the trunk and limbs of a swimmer. Numerous pilot studies were conducted to evaluate the effectiveness of different tuft materials, dimensions and methods of attachment for recording the characteristics of the flow around a swimmer performing various strokes and drills. Differences in the patterns of flow made visible by the tufts suggested that this method of flow visualization may well be useful in resolving both basic and applied questions concerning swimming techniques.     

Sex differences in motor characteristics of elementary school children included/not included in swimming training

The aim of the study was to assess the development of motor abilities in elementary school fifth- to eighth-graders (age 11-14 years) according to sex, age and physical activity. Study sample included 312 subjects divided according to age and sex into four groups: male subjects aged 11-12 (n = 93) and 13-14 years (n = 84); and female subjects aged 11-12 (n = 65) and 13-14 years (n = 70). Then, differences in basic motor abilities between children included (experimental group) and those not included (control group) in swimming training were analyzed. In male fifth- and sixth-graders, experimental group was superior to control group in the variables of trunk repetitive strength, sprint, flexibility and coordination, while in male seventh- and eighth-graders experimental group showed better performance than control group in agility, aerobic endurance and explosive throw and jump strength. In female fifth- and sixth-graders, experimental group proved superior to control group in the variables of explosive strength, coordination, trunk strength and aerobic endurance, whereas in female seventh- and eighth-graders experimental group had better performance in coordination, endurance, explosive strength, speed and flexibility. Discriminative analysis of motor variables between male and female subjects revealed male subjects to be superior in explosive strength, throw strength in particular, coordination and aerobic endurance, whereas female subjects showed better performance in the variables of flexibility and movement frequency, leg movement in particular. Study results showed the formation of appropriate motor system determining achievement of top results in swimming to be influenced by swimming training from age 11 to 14. In male children, motor system was found to integrate coordination/agility, aerobic endurance and explosive strength, whereas in female children it integrated coordination in terms of cortical movement regulation, aerobic endurance, explosive strength and psychomotor speed.     

四川绵阳地区肺炎链球菌流行病学特征

目的 了解四川绵阳地区肺炎链球菌的耐药情况,为临床合理用药及感染控制提供依据。方法 收集我院2015年1月至2017年12月临床分离的718株肺炎链球菌,并对其药物敏感性检测结果进行分析。结果 肺炎链球菌对红霉素和四环素的耐药率最高,均在95%以上;对左氧氟沙星、莫西沙星、泰利霉素、氯霉素的敏感性较高,均在89%以上;对青霉素、美罗培南、阿莫西林和头孢类抗生素的耐药率均在30%以上;未检出万古霉素和利奈唑胺耐药株。肺炎链球菌主要耐药模式为头孢曲松+红霉素+四环素+复方新诺明+美罗培南+青霉素+阿莫西林+头孢噻肟占19.44%。2017年肺炎链球菌青霉素敏感株和不敏感菌株对美罗培南、阿莫西林、厄他培南、头孢噻肟、头孢曲松、氧氟沙星、复方新诺明和氯霉素的不敏感率比较差异有统计学意义（P<0.05）。结论 本地区肺炎链球菌对红霉素、四环素耐药率较高,不适用于肺炎链球菌感染的治疗;对青霉素、美罗培南、阿莫西林和头孢类抗生素不敏感率较高,应慎重用于经验治疗;对万古霉素、利奈唑胺和喹诺酮类药物敏感性较高,临床可合理使用。     

The microbiological characteristics of intestinal dysbacteriosis in children and adults in the city of Moscow

The bacteriological analysis of 302 children has revealed that dysbacteriosis with the increased content of hemolytic Escherichia in the intestine develops more frequently in the presence of the deficiency of bifido- and lactobacteria. The development of other kinds of dysbacteriosis with the increased content of different opportunistic enterobacteria, staphylococci, enterococci and fungi, as well as dysbacteriosis with the decreased content of Escherichia, does not practically depend on the deficiency of bifido- and lactobacteria. In patients with the increased content of Escherichia an increase in the content of opportunistic enterobacteria, staphylococci and fungi is observed more frequently than in patients with the low content of Escherichia.     

Muscle fiber characteristics of competitive power lifters

To examine the skeletal muscle characteristics of power lifters, 5 competitive power lifters (PL; X +/- SE; age = 31.0 +/- 1.5 years, squat = 287.7 +/- 15.7 kg, bench press = 170.5 +/- 17.7 kg, and deadlift = 284.2 +/- 7.5 kg) and 5 untrained control subjects (CON; age = 27.3 +/- 3.3 years) served as subjects. Isokinetic squat force and power was greater (p < 0.05) for the PL at all bar velocities (0.20, 0.82, and 1.43 m;pd s(-1)), as was vertical jump height and estimated power. Muscle biopsies from the vastus lateralis m. revealed significant differences for percent fiber type (PL, IIA = 45.5 +/- 1.6%, IIB = 1.3 +/- 0.8%; CON, IIA = 33.4 +/- 3.1%, IIB = 12.0 +/- 2.4%); percent fiber type area (PL, IIA = 51.8 +/- 1.6%, IIB = 1.3 +/- 0.8%; CON, IIA = 43.5 +/- 3.4%, IIB = 12.4 +/- 2.6%); and percent myosin heavy chain isoform (PL, IIa = 59.5 +/- 6.1%; CON, 46.5 +/- 2.5%). Muscle fiber characteristics were significantly correlated (r = +/- 0.61) with numerous strength and power measures for the PL. These data illustrate the muscle fiber characteristics necessary for the maximal force production requirements of power lifting.     

Biological age in children who practise swimming.

In the estimation of the developmental regularity among children it is important to know the relation between the developmental and the calendar age. It is particularly important in the estimation of the level of development among children with an increased level of guided motor activity. It takes place, for instance, in the case of children practising swimming. In auxology there are many morphological, physiological and motor features which are regarded as the measure of the developmental age. For several years researches have been conducted on the EMN index as the determinant of the biological age. The EMN index shows continuous changes during ontogeny, proves the existence of stages in the developmental age and is also considerably correlated with the calendar age. This is an ecosensitive factor. The EMN index differentiates individuals from another as well as groups isolated with regard to the effect of the environmental factors, for instance, the different levels of motor activity. The aim of this investigation is to estimate the standard of biological maturity (the body height and mass, the EMN index) among children, who went through a guided swimming training. Morphological features are most often used as the measures of development. However, they can become unreliable when they themselves establish the criterion of selection to a sports discipline or when some ranges of values are optimal on some given standards. The EMN index is not burdened with these features. The children who go through training show the higher level of the EMN index values than the children who do not go. The effect of this is the fact that young swimmers are biologically older than their peers. However, the shape of the curve of development of the EMN index in swimmers goes at a different level depending on the seniority of training.     

Determination and validity of critical velocity as an index of swimming performance in the competitive swimmer.

The purpose of this investigation was to test whether the concept of critical power used in previous studies could be applied to the field of competitive swimming as critical swimming velocity (vcrit). The vcrit, defined as the swimming velocity over a very long period of time without exhaustion, was expressed as the slope of a straight line between swimming distance (dlim) at each speed (with six predetermined speeds) and the duration (tlim). Nine trained college swimmers underwent tests in a swimming flume to measure vcrit at those velocities until the onset of fatigue. A regression analysis of dlim on tlim calculated for each swimmer showed linear relationships (r2 greater than 0.998, P less than 0.01), and the slope coefficient signifying vcrit ranged from 1.062 to 1.262 m.s-1 with a mean of 1.166 (SD 0.052) m.s-1. Maximal oxygen consumption (VO2max), oxygen consumption (VO2) at anaerobic threshold, and the swimming also velocity at the onset of blood lactate accumulation (vOBLA) were also determined during the incremental swimming test. The vcrit showed significant positive correlations with VO2 at anaerobic threshold (r = 0.818, P less than 0.01), vOBLA (r = 0.949, P less than 0.01) and mean velocity of 400 m freestyle (r = 0.864, P less than 0.01). These data suggested that vcrit could be adopted as an index of endurance performance in competitive swimmers.     

Determinants of the microbiological characteristics of South Australian swimming pools

A survey of 100 swimming pools has been conducted to assess the effectiveness of disinfection practices against various microorganisms and to check compliance with recommended chlorine levels and pH. Microbiological quality was assessed from densities of total coliforms, Escherichia coli, and Pseudomonas aeruginosa, total colony counts, and the presence or absence of amoebae, including the pathogen Naegleria fowleri. Although a free chlorine residual of 1.0 mg/liter and a pH range of 7.0 to 7.6 are recommended by local health authorities, 41 pools had a lower free chlorine residual and 37 had a pH outside this range. Multiple logistic regression analysis was used to test the association of field measurements with the microbiological data. The analysis demonstrated a strong positive association of free chlorine with bacteriological quality and the absence of Naegleria spp. No other field measurement was predictive in this regard, although the absence of all amoebae was associated with a relatively low water temperature and pH. Using a mathematical model derived from this analysis, it was estimated that 99% of pools would have acceptable bacteriological quality and 94% would be free of Naegleria spp. at a free chlorine residual of 1.0 mg/liter. However, at the mean water temperature (23 degrees C) and pH (7.5) seen in this study, other amoebae would still be detectable in 500-ml samples taken from 40% of pools at this chlorine level.     

Determinants of the microbiological characteristics of South Australian swimming pools.

A survey of 100 swimming pools has been conducted to assess the effectiveness of disinfection practices against various microorganisms and to check compliance with recommended chlorine levels and pH. Microbiological quality was assessed from densities of total coliforms, Escherichia coli, and Pseudomonas aeruginosa, total colony counts, and the presence or absence of amoebae, including the pathogen Naegleria fowleri. Although a free chlorine residual of 1.0 mg/liter and a pH range of 7.0 to 7.6 are recommended by local health authorities, 41 pools had a lower free chlorine residual and 37 had a pH outside this range. Multiple logistic regression analysis was used to test the association of field measurements with the microbiological data. The analysis demonstrated a strong positive association of free chlorine with bacteriological quality and the absence of Naegleria spp. No other field measurement was predictive in this regard, although the absence of all amoebae was associated with a relatively low water temperature and pH. Using a mathematical model derived from this analysis, it was estimated that 99% of pools would have acceptable bacteriological quality and 94% would be free of Naegleria spp. at a free chlorine residual of 1.0 mg/liter. However, at the mean water temperature (23 degrees C) and pH (7.5) seen in this study, other amoebae would still be detectable in 500-ml samples taken from 40% of pools at this chlorine level.     

Isoflavones in children and adults consuming soy

Soy and their isoflavones (IFLs) are believed to protect against breast cancer, particularly when exposure occurs during childhood. Little is known about the bioavailability of IFLs in children and how this is affected by oral antibiotics (OABX). We measured IFLs by LC/MS and found that the urinary IFL excretion rate (UIER) reflects circulating IFLs accurately when area-under-curve (AUC) and identical time intervals are used (r = 0.93; p < 0.001). UIER in children and adults was determined when healthy and when on OABX by collecting urine in pairs of baseline and overnight specimen before and after consuming soy nuts, respectively. Compared to when healthy, children on OABX showed significantly decreased UIER but adults on OABX showed increased UIER (p < 0.05). All 37 healthy children showed significantly higher UIERs compared to all 34 healthy adults. UIER is an adequate surrogate for determining IFL bioavailability and for measuring soy or IFL exposure in epidemiologic and other studies.     

Therapeutic lung lavages in children and adults

Background

Pulmonary alveolar proteinosis (PAP) is a rare disease, characterized by excessive intra-alveolar accumulation of surfactant lipids and proteins. Therapeutic whole lung lavages are currently the principle therapeutic option in adults. Not much is known on the kinetics of the wash out process, especially in children.

Methods

In 4 pediatric and 6 adult PAP patients 45 therapeutic half lung lavages were investigated retrospectively. Total protein, protein concentration and, in one child with a surfactant protein C mutation, aberrant pro-SP-C protein, were determined during wash out.

Results

The removal of protein from the lungs followed an exponential decline and averaged for adult patients 2 – 20 g and <0.5 to 6 g for pediatric patients. The average protein concentration of consecutive portions was the same in all patient groups, however was elevated in pediatric patients when expressed per body weight. The amount of an aberrant pro-SP-C protein, which was present in one patient with a SP-C mutation, constantly decreased with ongoing lavage. Measuring the optical density of the lavage fluid obtained allowed to monitor the wash out process during the lavages at the bedside and to determine the termination of the lavage procedure at normal protein concentration.

Conclusion

Following therapeutic half lung lavages by biochemical variables may help to estimate the degree of alveolar filling with proteinaceous material and to improve the efficiency of the wash out, especially in children.