Effect of Solution Stoichiometry on BaSO4 Crystallization from Turbidity Measurements and Modeling

The impact of solution stoichiometry on the nucleation and growth of BaSO4 was studied by measuring solution transmittance and subsequent fitting to a crystallization model. Our results show that a large excess of either Ba2+ or SO42- ions inhibits both the nucleation and growth of BaSO4. However, for a small excess of Ba2+, the growth is enhanced. The dependence of nucleation and growth rates on supersaturation and solution stoichiometry was captured by a semiempirical rate model. Hence, the solution stoichiometry is a highly relevant parameter while studying all aspects of BaSO4 crystallization, and it could be worthwhile to examine other minerals similarly.

Customer Loyalty in Recreational Long-Distance Races: Differences Between Novice and Experienced Runners

A growing number of recreational races are being held in different locations, drawing many local and visiting runners. This study examined the relationships between quality, value, satisfaction, and loyalty among runners in a recreational race and examines potential differences in relationships between these constructs based on the runners’ experience. The participants were 985 runners with a mean age of 40.74±9.41years. Validated, reliable ad hoc instruments were used. A multi-group analysis was performed to ascertain the existence of relationships between the constructs and differences in the relationships between the different study groups. The results show that quality is a direct antecedent of value and satisfaction. Value is directly related to satisfaction and indirectly related to loyalty. Satisfaction is related to the loyalty of participants in the race. Differences in the relationship between satisfaction and loyalty were dependent upon the runners’ experience. Loyalty to a race depends primarily on satisfaction and is modified by the runners’ experience.

Consolidation, Stages of Change, and Loyalty among Users of Public Sports and Health Services Aged 12-16

There are two main lines of inquiry in the literature on adherence and/or loyalty to the practice of physical activity and to health services: one focuses on the impact of perceived quality of sports and health services and satisfaction with these services on user loyalty, while the other concludes that users with more self-determined motivation at more advanced stages of physical activity display higher levels of physical activity and greater intentions to continue this activity. The objective of this study is to ascertain the impact of different dimensions of sports service quality on satisfaction and loyalty among users aged 12 to 16 years old and to identify any differences between adolescent users at more and less consolidated stages of physical activity. A total of 1717 minors with a mean age of 13.83 ± 1.32 years who practise organised physical activity at public sports centres in Nuevo León (Mexico), 51.5% of whom were boys, participated in the study. The model of structural equations linking quality, satisfaction, and loyalty displayed adequate indices. The results showed that the staff, specific activity, and user satisfaction are predictors of loyalty. Significant differences were only found between minors at consolidated and non-consolidated stages of physical activity in the relationship between service personnel and loyalty. In conclusion, human resources and their deployment are predictive of loyalty towards sports and health services among adolescents.

Women and Physical Activity in Fitness Centres. Analysis of Future Intentions and Their Relationship with Age

Physical activity is an important tool for promoting women's health. Increasing adherence to physical activity is a challenge for governments and private entities. One of the main objectives of the fitness sector is to build customer loyalty. Their behavioural intentions according to gender and age may be a determining factor. The aim of this study was to establish a model that relates the fitness centre's quality as perceived by female customers, these customers' future intentions, satisfaction, and age. A total of 745 women participated in this study, with a mean age of 32.97 ± 14.11, divided into three age groups. A confirmatory analysis, a factor invariance analysis, and a multi-group analysis were conducted to verify the validity and reliability of the model. The results revealed that quality is an antecedent of both perceived value and satisfaction in the three age groups. Perceived value is a precursor of satisfaction, except in the group of women over 45 years old. The only antecedent to adaptation to price is quality, except in the older age group. Finally, perceived value was found to be related to adaptation to price. These results will facilitate the development of strategies to promote physical activity among women according to their age.

Communication as a Strategy to Promote Sports and Health Activities Designed for Adolescents

Physical activity reduces the risk of developing noncommunicable diseases and improves quality of life, providing health benefits for present and future generations. This is especially relevant for adolescents. Educational institutions are promoters of healthy habits through the organisation of different activities such as extracurricular sports programmes. These activities increase the rates of sports practice among adolescents. The literature shows that the perceived quality of sports and health services is an antecedent of users' behavioural intentions. The aim of this paper is to find out whether communication from educational/sports organisations influences adolescents' intentions to continue engaging in physical activity. A total of 1080 students participated, with a mean age of 13.76 ± 1.39 years, 34.1% of whom were girls. Tests were conducted to verify the validity and reliability of the model that relates communication with value, satisfaction, and future intentions. Tests were conducted to verify the validity (average variance extracted was between 0.754 and 0.583) and reliability (composite reliability was between 0.925 and 0.813) of the model that relates communication with value, satisfaction, and future intentions. Confirmatory analyses and factor invariance tests were performed. The results revealed that communication is an antecedent of value, satisfaction, and future intentions. In conclusion, communication is a good strategy to consolidate sporting habits in both male and female adolescents.

Lead(ii) soaps: crystal structures, polymorphism, and solid and liquid mesophases

The long-chain members of the lead(ii) alkanoate series or soaps, from octanoate to octadecanoate, have been thoroughly characterized by means of XRD, PDF analysis, DSC, FTIR, ssNMR and other techniques, in all their phases and mesophases. The crystal structures at room temperature of all of the members of the series are now solved, showing the existence of two polymorphic forms in the room temperature crystal phase, different to short and long-chain members. Only nonanoate and decanoate present both forms, and this polymorphism is proven to be monotropic. At higher temperature, these compounds present a solid mesophase, defined as rotator, a liquid crystal phase and a liquid phase, all of which have a similar local arrangement. Since some lead(ii) soaps appear as degradation compounds in oil paintings, the solved crystal structures of lead(ii) soaps can now be used as fingerprints for their detection using X-ray diffraction. Pair distribution function analysis on these compounds is very similar in the same phases and mesophases for the different members, showing the same short range order. This observation suggests that this technique could also be used in the detection of these compounds in disordered phases or in the initial stages of formation in paintings.

Intention to be Physically Active is Influenced by Physical Activity and Fitness, Sedentary Behaviours, and Life Satisfaction in Adolescents

The aim of this study was to determine the association of levels of physical activity (PA), physical fitness (PF), sedentary lifestyle and life satisfaction with the intention to be physically active after secondary school graduation, in teenagers of both genders. A total of 1986 Spanish adolescents (12-16 years) participated in this cross-sectional study. PA, sedentary lifestyle, life satisfaction and intention to be physically active were assessed through validated questionnaires, and PF was evaluated objectively with the ALPHA battery tests. In both genders, adolescents who had significantly higher odds ratios (OR) of showing low intention to be physically active had low level of PA, cardiorespiratory fitness and muscular fitness in the lower body, and they were more sedentary in front of the computer. The girls that spent a lot of time watching TV and the boys with low life satisfaction also showed higher OR of having low intention to be physically active.

Relationship of physical activity and sedentarism with tobacco and alcohol consumption, and Mediterranean diet in Spanish teenagers

BACKGROUND AND OBJECTIVES

This study examined the association of physical activity and sedentarism with tobacco and alcohol consumption, and adherence to the Mediterranean diet in teenagers of both genders.

METHODS

A total number of 1897 Spanish teenagers (12-16 year-olds) took part in the present cross-sectional study. The variables were measured by means of questionnaires previously validated for these ages.

RESULTS

Physical activity was positively associated to the degree of adherence to the Mediterranean diet for both genders (ß = .144, P < .001 for boys and ß = .066, P< .05 for girls), and inversely associated to smoking for boys (ß = -.135, P = <.001). Sedentary behaviors for leisure purposes (TV and PC) were negatively associated to adherence to the Mediterranean diet for both boys (ß =-.100 and ß = -.104, both P < .05, respectively) and girls (ß= -.148 and ß = -.141, both P <.001), and positively associated to alcohol consumption for girls (ß = .114, P < .01 and ß = .199, P < .001, respectively).

CONCLUSION

results suggest that physical activity and sedentary behaviors have an important relationship with the adherence to the Mediterranean diet in teenagers. Also, higher levels of physical activity in boys can lead to reduced tobacco use, while watching TV and PC leisure can lead to increased alcohol consumption in girls.

[Adherence to the Mediterranean diet in rural and urban adolescents of southern Spain, life satisfaction, anthropometry, and physical and sedentary activities]

BACKGROUND

The Mediterranean diet is one of the healthier diet models. Mediterranean food patterns are suffering a deterioration that can especially affect children and adolescents.

OBJECTIVE

Determine adherence to the Mediterranean diet in adolescents of southern Spain and its relationship with the residence area, sex, age, life satisfaction, anthropometry, and habits of physical activity and sedentary activities.

METHODOLOGY

A total of 1973 adolescents (11-18 years) of southern Spain participated in this descriptive cross-sectional study. Cut-off value between rural and urban locations was 10000 inhabitants. Adherence to the Mediterranean diet was calculated from the KIDMED questionnaire. Life satisfaction, physical activity, and sedentary activities also were measured through valid and reliable questionnaires. Body mass index and % body fat were measured using the TANITA BC-420-S body analyzer.

RESULTS

30.9% of the adolescents reported an optimal quality diet, percent higher in rural locations (P < 0.05). Adherence was lower in older adolescents (P < 0.001), it was not different between sexes or according to anthropometric variables. Adolescents more satisfied with their lives (P < 0.001), more active (P < 0.001), more studious (P < 0.001), and less sedentary in front of a screen (P < 0.001) showed greater adherence to the Mediterranean food pattern.

CONCLUSION

The majority of adolescents need to improve their nutritional quality. Compared with these subjects, the adolescents most adherent to the Mediterranean diet had a healthier lifestyle and they showed greater life satisfaction.

Increased intrahepatic cyclooxygenase 2, matrix metalloproteinase 2, and matrix metalloproteinase 9 expression is associated with progressive liver disease in chronic hepatitis C virus infection: role of viral core and NS5A proteins

BACKGROUND

Cyclooxygenase 2 (COX-2) and matrix metalloproteinases (MMPs) have been implicated in tissue injury and fibrogenesis in animal models but little is known regarding their role in hepatitis C virus (HCV) related liver disease in humans.

AIMS

To characterise the intrahepatic expression pattern of COX-2 and MMPs in chronic HCV infection and determine whether HCV core and NS5A proteins could promote their expression in cultured hepatocyte derived cell lines.

PATIENTS

Thirty two anti-HCV+ and 10 anti-HCV- patients were studied.

METHODS

Western blot, reverse transcription-polymerase chain reaction (RT-PCR), enzyme immunoassay, and immunohistochemistry were used to assess the expression pattern of COX-2 and MMPs in liver biopsy samples from all patients. COX-2 gene expression and MMP-9 protein levels were also determined by immunoblot, RT-PCR, and luciferase assays in core and NS5A transfected hepatocyte derived cells.

RESULTS

The intrahepatic expression level of COX-2, MMP-2, and MMP-9 was significantly higher in HCV+ than in HCV- patients, increasing with the fibrotic stage of liver disease. We further demonstrated that COX-2 mRNA, protein, and activity were induced in resting and activated core and NS5A transfectants. Both viral proteins induced transcriptional activity of the COX-2 gene promoter whereas core, but not NS5A, exerted an inducer effect on MMP-9 protein levels in cultured hepatocyte derived cells.

CONCLUSIONS

Intrahepatic COX-2, MMP-2, and MMP-9 overexpression is associated with progressive hepatic fibrosis in chronic HCV infection, suggesting their pathogenic role in fibrogenesis. HCV core and NS5A proteins were able to upregulate COX-2 and MMP-9 gene expression in hepatocyte derived cells, providing a potential mechanism for hepatic fibrosis during chronic HCV infection.

[Ultrasound diagnosis of salivary gland tumors]

The ultrasonic diagnosis of salivary gland tumors can give a more accurate information than clinical data alone. For example, it will help differentiate intraglandular from extraglandular tumors and benign from malignant processes. We conducted a prospective study in 39 patients with parotidal or submaxillary tumors. Patients were evaluated with a physical exam and a with ultrasound. Results indicate that only 53.86% of the physical examinations were correct in their diagnosis compared to 87.18% of the those done by ultrasound. Specificity and sensibility for malignancy was 96.43% and 81.81% respectively. These results were similar to those reported by other authors. We conclude that the use of ultrasound techniques in the study of salivary gland pathology is well justified, due to its capacity to provide high resolution, improving clinical diagnosis.