Kinetics of acoustic release of doxorubicin from stabilized and unstabilized micelles and the effect of temperature

Ultrasound is being investigated as a trigger mechanism to deliver high concentrations of chemotherapy drugs to cancerous tissues using polymeric micelles. In this paper, we examined the kinetics of acoustic release of doxorubicin using stabilized and non-stabilized micelles. Kinetic models were used to regress release and re-encapsulation time constants for three different compounds, namely non-stabilized Pluronic^® P105 micelles, P105 micelles stabilized using an interpenetrating network of N,N-diethylacrylamide and micelles formed by PEO-b-poly(NIPAAm-co-HEMA-lactate_n). Results showed that the kinetic release constant (k_r) depends on the micellar system under investigation. On the other hand, there is no statistically significant difference between re-encapsulation rate constants for stabilized and unstabilized micelles. We hypothesize that k_r depends on the degree of cross-linking or stabilization.     

Do linkages between farmers and academic researchers influence researcher productivity? The Mexican case

A growing body of literature is focusing on how the collaborations researchers engage in affect their productivity. Most authors have focused on linkages among academic researchers, measuring productivity by the number of papers published in ISI journals. In contrast, the impact of interactions between academic researchers and the business sector on research productivity has been less analyzed. The aim of this paper is to analyze how broadly defined research productivity (papers, new recommendations and new techniques) in agriculture-related fields is affected by the nature of academy-farmers interactions. This latter was approached through two dimensions: the breadth of linkages and their intensity, measured by the duration, in two different modalities (R&D activities and consultancy). Based on original micro data obtained through a survey of researchers working in universities and PRCs in agriculture-related fields, we built three models, one per output, to identify the effect of the nature of interactions on research productivity. The models were estimated with a negative binomial distribution using Maximum Likelihood estimators. We found a positive relationship between interaction with farmers and publishing of papers when interactions are carried out through the R&D modality. We also found that the impact of the nature of interactions on research productivity differs according to the type of research output. The impact is broader in the case of new recommendations than in the other outputs. The production of new recommendations is positively influenced by both the breadth of linkages and their duration through both modalities of interaction (R&D and consultancy).     

Cardiac troponins and physical exercise. It's time to make a point

The timely diagnosis of acute coronary syndrome (ACS), in particular myocardial infarction (MI), is still one of the most challenging issues in medicine. The introduction into routine laboratory practice of assays for measuring the cardiospecific troponins has dramatically revolutionized the diagnostic approach and the recent development of methods with improved analytical sensibility (i.e., highly sensitivity [HS] assays), has further contributed to improve the negative predictive value of troponin testing but, contextually, has substantially lowered the clinical specificity of these markers. In particular, clinical studies have demonstrated the existence of an exercise-related increase of HS-troponins, with measurable values detectable in up to 94% of athletes undergoing endurance sports. This measurable amount oftroponin in blood would mirror an increased membrane permeability and early troponin release rather than reflecting a clinically threatening myocardial injury. As such, the measurable amount of cardiac troponins as assessed with the novel HS assays requires major clinical focus (i.e., serial measurement of cardiac biomarkers, detailed clinical history-taking, integration with ECG and imaging findings) to prevent misdiagnosis of ACS and/or MI in otherwise healthy persons.     

A Cultural Comparison of Trust in eLearning Artifacts

A significant body of literature focuses on learning mediated by technology (eLearning). We conceptually develop and empirically test a model of trust antecedents with online undergraduate students. Contributing to the student eLearning success literature, we posit that eLearning students require the support of technologies and trust in those technologies to feel satisfied with their learning and perceive that they will have a positive learning outcome. This study considers the effect of culture by comparing the trust and satisfaction of American and Latin American students in eLearning technologies. By conducting this study in two countries that differ in terms of national culture power distance and individualism, we learned that culture directly and significantly impacts trust in learning technologies. Culture also significantly changes the strength of the relation between trust and satisfaction. Future research directions and implications for researchers and higher education instructors are discussed.     

Does Quantum Physics Refute Realism, Materialism and Determinism?

It is argued that the correct answer to the three questions in the title is ??no??: that the theses being denied derive from traditional philosophy, not from the way the quantum theories are used. For example, the calculation of the energy spectrum of an atom assumes the autonomous existence of the atom, rather than its dependence upon the observer. However, it is also suggested that the problem has been unnecessarily complicated by a careless use of the terms ??realism??, ??materialism??, and ??determinism??. Precise definitions of these words are proposed.     

An empirical test of anchoring the NEP scale in environmental ethics

Some argue that the new ecological paradigm (NEP) scale is incomplete and does not adequately reflect contemporary debates in environmental ethics. We focus on one specific shortcoming of the NEP, its lack of an item to reflect an ecocentric viewpoint. To test this concern, we administered the NEP to three different audiences and included one additional item to capture an ecocentric perspective. The empirical tests were designed to determine whether the addition of such an item changed results in a meaningful way. We find evidence that NEP may already capture ecocentric viewpoints, but our investigation leads us to question the validity and reliability of the NEP in capturing ecological worldview.     

Implicaciones educativas de los estilos cognitivos

RESUMEN

Se plantea el problema de la adecuación de los contenidos y las técnicas educativas a los estilos cognitivos del alumno. Muchas investigaciones han mostrado la relación entre reflexividad-impulsividad y rendimiento escolar. Nuestro sistema educativo actual parece favorecer las habilidades propias de los sujetos reflexivos. En este sentido, muchos trabajos han investigado los procedimientos para modificar el estilo cognitivo hacia la reflexividad, ya que este estilo se considera más adaptativo. En relación al estilo cognitivo dependencia-independencia de campo (DIC) se han encontrado diferencias en el aprendizaje según los contenidos, el tipo de reforzamiento, las diferentes formas de motivación (extrínseca o intrínseca) y los “mediadores del aprendizaje” utilizados. Se plantea la necesidad de adaptar los contenidos y los procedimientos a las necesidades de los distintos alumnos, y la de encontrar la manera de ayudarlos a diversificar sus estrategias de aprendizaje.     

Ubiquitous computing in sports: A review and analysis

Abstract

Ubiquitous (pervasive) computing is a term for a synergetic use of sensing, communication and computing. Pervasive use of computing has seen a rapid increase in the current decade. This development has propagated in applied sport science and everyday life.

The work presents a survey of recent developments in sport and leisure with emphasis on technology and computational techniques. A detailed analysis on new technological developments is performed. Sensors for position and motion detection, and such for equipment and physiological monitoring are discussed. Aspects of novel trends in communication technologies and data processing are outlined.

Computational advancements have started a new trend – development of smart and intelligent systems for a wide range of applications – from model-based posture recognition to context awareness algorithms for nutrition monitoring. Examples particular to coaching and training are discussed. Selected tools for monitoring rules' compliance and automatic decision-making are outlined. Finally, applications in leisure and entertainment are presented, from systems supporting physical activity to systems providing motivation.

It is concluded that the emphasis in future will shift from technologies to intelligent systems that allow for enhanced social interaction as efforts need to be made to improve user-friendliness and standardisation of measurement and transmission protocols.     

Squat Jump Performance During Growth in Both Sexes

The purpose of this cross-sectional study was to investigate leg muscle power and compare two activities (jumping and cycling) in 383 girls and 407 boys ages 9–19 years. Results in anthropometric characteristics and jumping performance were comparable until midadolescence, and sex differences were observed. Lean leg volume (LLV) was the reason for most of the variance (76% in girls and 88% in boys) in jumping performance. However, the LLV exponent was higher than expected in boys but not girls. Therefore, unidentified qualitative changes of muscle function during growth in boys must be considered. The squat jump index (SJI) was highly correlated to cycling peak power (CPP; N = 790, r = .94, p < .001). Although prediction error of CPP from SJI was less than 5% when considering each sex-and-age group, individual errors mounted to 40%. Due to its practicability, SJI is recommended in large-scale developmental prospective studies. However, cycling and jumping protocols are not interchangeable when measuring peak power values.