Sun-related behaviors, attitudes and knowledge among paralympic sailors.

BACKGROUND: Overexposure to sunlight is the main cause of skin cancer. Outdoor sports increased sun exposure times. Sun protection behaviors and attitudes are utmost importance to reduce sun exposure. AIMS: To evaluate sun exposure habits, sun protection practices, and sun-related attitudes and knowledge among paralympic sailors. METHODS: This descriptive observational study analysed the answers of a validated self-reported questionnaire of habits, attitudes and knowledge related to sun exposure and skin cancer completed by 56 elite sailors with disabilities from 19 countries which taking part in 2019 Para World Sailing Championships. RESULTS: Three in four (76.8%) participants reported a history of sunburn in the previous season. Overall, participants showed an average for sport practice per week of 8.0 h (SD: 4.9). Participants reported a low adherence to sun protection practice, with the exception of using sunglasses (85.7%), sunscreen (83.9%) and hat (75%), having a very low rate (28.6%) of avoidance of midday sun and an inadequate sunscreen reapplication (33.9% reported "do not reapply" and 16.1% "reapply every one or 2 h"). Although 82.1% of participants reported to be worried about can get skin cancer out of the sun, they also presented excessive sun tanning attitudes (42.9% likes sunbathing and 57.1% sunbathing makes them feel well). The average score for sun-related knowledge was low (62.1 out 100 points; SD: 13.6). CONCLUSIONS: Awareness campaigns on sun risk are needed specifically directed at this target group, in order to improve their sun protection habits and reduce the rates of sunburn associated with sports practice.

Impact of a physical activity program on cerebral vasoreactivity in sedentary elderly people.

AIM: The aim of the present study was to determine the effect of a physical activity program on the hemodynamic response of the brain (vasoreactivity) in elderly people. METHODS: Eighteen men and 25 women (aged 62-67 years) were randomly assigned to an experimental (EXP, N.=22, 12 women) and a control (CON, N.=21, 13 women) group. Subjects in EXP group were required to complete a 7-month program based on aerobic training (3-4 sessions/weekd, 50 min/session, 3-4 sessions/week, at 70% maximum heart rate). Transcranial Doppler ultrasound was used to examine the cerebral blood flow response to hypercapnic and hypocapnic stimuli. We also determined blood pressure, total serum cholesterol, HDL and LDL cholesterol, and triglycerides, and conducted an aerobic capacity test (the 2.4-Km walking test). RESULTS.Brain vasomotor reactivity improved in the EXP group, reflected by a higher blood flow velocity in the middle cerebral artery (MCA) in both cerebral hemispheres in response to hypercapnia (induced by breath holding) (P<0.05). Subjects in EXP group also improved the cardiovascular profile aerobic physical condition (P<0.001) in terms of reduced arterial pressure, total cholesterol and triglyceride levels. CONCLUSION: Our findings indicate that cerebral vasoreactivity in elderly may be improved by undertaking an aerobic exercise program.

Percentile values for aerobic performance running/walking field tests in children aged 6 to 17 years: influence of weight status.

The aim of this study was to provide percentiles values for four different aerobic performance tests in 2752 (1,261 girls) Spanish children aged 6 to 17.9 years. Aerobic performance was assessed by the shuttle run test (20 mSRT), 1-mile, 1/2-mile and 1/4-mile run/walk tests. Height and weight were measured, and body mass index was calculated. Boys had significantly better score than girls in the studied tests in all age groups, except in 1/4-mile test in 6-7 year old children. Underweight children had similar performance than their normalweight counterparts, and underweight boys had better performance than their obese counterparts. Overweight and obese children had lower performance than their normalweight counterparts. Having percentile values of the most used field tests to measure aerobic performance in youth may help to identify children and adolescents at risk for the major chronic diseases, as well as to evaluate the effects of alternative interventions.

[Health behaviour of school children at the province of Cádiz]. / Conductas de salud en escolares de la provincia de Cádiz.

OBJECTIVE: The aim of this study was to analyze some characteristics of health-related behaviour in school children at the province of Cadiz, centering on engagement in sports and physical activity, and on dietary habits. METHODOLOGY: Participants were 738 students, mean age 12.2 years, from primary school o high school. 50.9% were boys and 49.1% girls, who responded a Spanish adaptation of the Health Behavior in Schoolchildren Inventory. RESULTS: Sex differences were observed in the percentage of subjects not engaged in sports, which was higher in girls. Boys practiced sports and physical activity at a higher intensity and more time than girls. A large number of subjects considered good or normal their physical fitness, with only and small percentage describing it as regular. More than half of participants felt a support by parents, and to a smaller extent by brothers and friends. An important part of the subjects did not have breakfast every day, and some even never. A high percentage of the sample ate candies 1 to 3 days per week, being also high the intake of chips, nuts, hamburgers and sausages. Near a quarter of subjects reported not to consume vegetables. CONCLUSIONS: Results obtained confirm the necessity of an adequate lifestyle habits education and the development of intervention programs in children and youth, counseling on diet and physical activity and targeting on girls, who are less physically active and on risk of serious disorders.

Criterion-related validity of sit-and-reach and modified sit-and-reach test for estimating hamstring flexibility in children and adolescents aged 6-17 years.

The purpose of the present study was to examine the criterion-related validity of the sit-and-reach test (SRT) and the modified sit-and-reach test (MSRT) for estimating hamstring flexibility in children and adolescents as well as to determine whether the MSRT is more valid than the SRT. A total of 87 (45 boys and 42 girls) children (6-12 years old) and adolescents (13-17 years old) performed the SRT and the MSRT. Hamstring flexibility was measured with goniometry through the passive straight-leg raise test. Regression analysis was performed to study the association of SRT and MSRT with hamstring flexibility (criterion measure). The SRT was associated with hamstring flexibility in both children (beta=1.089, R (2)=0.281, p=0.001) and adolescents (beta=0.690, R (2)=0.333, p=0.004). The MSRT was also associated with hamstring flexibility in both children (beta=1.296, R (2)=0.298, p<0.001) and adolescents (beta=0.588, R (2)=0.243, p=0.027). It is concluded that the criterion-related validity of the SRT and the MSRT for estimating hamstring flexibility is weak. The present data do not support that the MSRT is a more valid method than the SRT in children and adolescents.

Improving the monitoring of methanol concentration during high cell density fermentation of Pichia pastoris.

The Pichia pastoris expression system is widely used for the production of recombinant proteins. A simple and efficient experimental set-up allowing on-line monitoring of the methanol concentration during the fermentation of P. pastoris based on the detection of the methanol vapor concentration in the exhaust air from fermenter by a tin dioxide (SnO2) semiconductor sensor is described. An experimental procedure to allow precise calibration of the system and to reduce methanol sensor's interferences (>95% reduction) are also presented and discussed. Accuracy and measurement error were estimated about 0.05 g x l(-1) and 6%, respectively. The efficient monitoring of methanol will help to advanced control of recombinant protein production and process optimization.

On-line monitoring of the methanol concentration in Pichia pastoris cultures producing an heterologous lipase by sequential injection analysis.

An automated sequential injection analysis (SIA) system using stop-flow technique was developed to determine methanol concentration by means of the enzymatic reactions of alcohol oxidase and peroxidase. Its application as an on-line device for monitoring Pichia pastoris fermentations producing an heterologous protein was demonstrated. Linear response, observed up to 2 g l(-1), was reached by including a dilution chamber in the SIA manifold. The sampling frequency was 7 analyses per hour with a relative standard deviation lower than 4%.

MELISSA: a loop of interconnected bioreactors to develop life support in space.

The development of a loop of interconnected continuous bioreactors, aimed to provide life support in space, is reported. The complete loop concept consists of four bioreactors and one higher plant compartment. For its realization the continuous and controlled operation of the bioreactors is characterized, up to the pilot scale level, first for each individual reactor, second for the interconnected reactor operation. The results obtained with the two more advanced bioreactors in the Micro Ecological Life Support System Alternative (MELISSA) loop are described more specifically. These reactors consist of a packed-bed reactor working with an immobilized co-culture of Nitrosomonas and Nitrobacter cells, and an external loop gas-lift photobioreactor for the culture of the cyanobacteria Spirulina platensis. Their individual operation for long duration runs has been achieved and characterized, and their interconnected operation at pilot scale is reported.

Production of native and recombinant lipases by Candida rugosa: a review.

The yeast Candida rugosa produces multiple lipase isoenzymes sharing high sequence homology but with some differences in their catalytic properties. The regulation of C. rugosa lipase (CRL) synthesis and secretion in C. rugosa obeys a complex pattern. Fermentation processes for both wild-type and mutant C. rugosa strains are available for lipase production. Native CRL preparations have been extensively used for biotransformations. However, their inherent mixture of isoforms with variable profiles complicates interpretation and brings into question the reproducibility achieved between preparations. Although heterologous CRLs gene expression had been hampered owing to a nonuniversal codon usage, recent advances have made heterologous CRLs available. This will expand and improve the industrial utility of CRLs even further. The purpose of this review is to provide a summary of the recent advances on the production of native and recombinant lipases by C. rugosa.

Improving lipase production from Candida rugosa by a biochemical engineering approach.

It has been tested that the use of oleic acid as sole carbon source and as inducer of the production has an important effect in the lipase production by Candida rugosa under aerobic conditions. A simple structured mathematical model coupled with a methodology to estimate biomass, specific growth rate and substrate was developed and applied to the production of Candida rugosa lipase in batch, fed-batch and continuous operation to obtain a reproducible product. The best operation mode tested was a controlled specific growth rate fed-batch with a 10-fold increase in productivity related to batch operation. Downstream of the culture broth has demonstrated that the ratio between the different isoenzymes presented can be modulated by the selection of the operational strategy and this ratio is quite different comparing with commercial lipases. Thus, their catalytic properties in front of chiral reactions could be different.

Physiological control on the expression and secretion of Candida rugosa lipase.

The fungus Candida rugosa secretes an extracellular lipase whose production is induced by the addition of fatty acids to the culture broth. This lipase is indeed composed by several protein isoforms partly differing in their catalytic properties. Synthesis and secretion of lipase proteins by C. rugosa cells were studied in culture media containing either glucose or oleic acid as the carbon source. It was shown that, according to their regulation, lipase-encoding genes might be grouped in two classes, one of which is constitutively expressed and the other is induced by fatty acids. The synthesis of inducible enzymes is inhibited at the level of transcription by the addition of glucose and, conversely, oleic acid appears to hinder the synthesis of the constitutive lipase. Growth conditions supporting high level expression both in batch and in continuous culture give rise to the intracellular accumulation of enzyme, possibly due to the existence of a rate-limiting step in the transport of the newly synthesized protein. These results suggest the possibility to develop fermentation processes aimed at the control of the enzyme composition.

Enhancement of Candida rugosa lipase production by using different control fed-batch operational strategies.

Simulation studies have predicted that maximum lipase activity is reached with fed-batch operation strategies. In this work, two different fed-batch operational strategies have been studied: constant substrate feeding rate and specific growth rate control. A constant substrate feeding rate strategy showed that maximum aqueous lipolytic activity (55 U/mL) was reached at low substrate feeding rates, whereas lipase tends to accumulate inside the cell at higher rates of substrate addition. In the second fed-batch strategy studied, a feedback control strategy has been developed based on the estimation of state variables (X and mu) from the measurement of indirect variables such as CER by means of mass spectrometry techniques. An on-off controller was then used to maintain the specific growth rate at the desired value by adjusting the substrate feeding rate. A constant specific growth rate strategy gave higher final levels of aqueous lipolytic activity (117 U/mL) at low specific growth rates. At higher specific growth rates the enzyme remained accumulated inside the cell, as was observed with a constant feeding fed-batch strategy. With a constant specific growth rate strategy, lipase production by Candida rugosa was enhanced 10-fold compared to a batch operation. Purification studies have demonstrated that lipolytic and esterasic specific activity ratios of Candida rugosa isoenzymes can be modified by using different operational conditions. These studies have also showed that the isoenzymes obtained in a controlled growth rate strategy are around three- to four-fold more active than those obtained in a constant feeding rate strategy.

Structured modeling and state estimation in a fermentation process: Lipase production by Candida rugosa.

A simple structured mathematical model coupled with a methodology of state and parameter estimation is developed for lipase production by Candida rugosa in batch fermentation. The model describes the system according to the following qualitative observations and hypothesis: Lipase production is induced by extracellular oleic acid present in the medium. The acid is transported into the cell where it is consumed, transformed, and stored. Lipase is excreted to the medium where it is distributed between the available oil-water interphase and aqueous phase. Cell growth is modulated by the intracellular substrate concentration. Model parameters have been determined and the whole model validated against experiments not used in their determination. The estimation problem consists in the estimation of three state variables (biomass, intra- and extracellular substrate) and two kinetic parameters by using only the on-line measurement provided by exhaust gas analysis. The presented estimation strategy divides the complex problem into three subproblems that can be solved by stable algorithms. The estimation of biomass (X) and the specific growth rate (mu), is achieved by a recursive prediction error algorithm using the on-line measurement of the carbon dioxide evolution rate. mu is then used to perform an estimation of intracellular substrate and the other kinetic parameter related to substrate transport (A) by an adaptive observer. Extracellular substrate is then evaluated by means of the estimated values of intracellular substrate and biomass through the material balance of the reactor. Simulation and experimental tests showed good performance of the developed estimator, which appears suitable to be used for process control and monitoring. (c) 1995 John Wiley & Sons, Inc.

Stability studies and effect of the initial oleic acid concentration on lipase production by Candida rugosa.

The production of lipase by Candida rugosa in batch cultures was studied. The initial concentration of the carbon source employed, oleic acid, had an important effect on the final lipolytic activity levels. The maximum lipase/substrate yield and specific productivity obtained correspond to an initial oleic acid concentration of 2 g/l. At higher concentrations, up to 8 g/l oleic acid, specific productivity decreased. Lipase production was not observed below 1 g/l oleic acid. Lipase inactivation in culture broth due to surface forces and shear stress at the gas/liquid interface was not observed. There was no shear stress denaturation at stirring rates of 250, 500 and 750 rpm. No temperature inactivation was detected up to 50 degrees C. Two different lipases with a similar molecular weight of 60 kDa were purified from culture broth.

Optimal design of an enzymatic reactor for flow injection analysis.

A simulation procedure for the optimization of enzymatic reactors used in sandwich flow injection systems is evaluated. The system is modeled as a plug-flow reactor with axial dispersion. To calibrate it, dispersion coefficients can be evaluated using residence time distribution techniques; meanwhile, enzymatic kinetics must be determined for the system considered, according to the values of the substrate conversion attained. The model has been linked to an optimization routine based on the Powell algorithm. The proposed approach has been evaluated in a system performing simultaneous determinations of glucose and glycerol, considered the common carbon sources in a fermentation process.

[Pneumatosis cystoides intestinalis revisited]. / La pneumatose kystique intestinale reconsidérée.

Two cases of pneumatosis cystoides coli are reported. The authors present an anatomic and physiopathologic review of the entity and give the list of etiologies with the worse prognosis. The radiologic signs are described and their contribution to an accurate diagnosis is stressed, as it may avoid useless surgical interventions.