Microfluidic-driven viral infection on cell cultures: Theoretical and experimental study

Advanced cell culture systems creating a controlled and predictable microenvironment together with computational modeling may be useful tools to optimize the efficiency of cell infections. In this paper, we will present a phenomenological study of a virus-host infection system, and the development of a multilayered microfluidic platform used to accurately tune the virus delivery from a diffusive-limited regime to a convective-dominated regime. Mathematical models predicted the convective-diffusive regimes developed within the system itself and determined the dominating mass transport phenomena. Adenoviral vectors carrying the enhanced green fluorescent protein (EGFP) transgene were used at different multiplicities of infection (MOI) to infect multiple cell types, both in standard static and in perfused conditions. Our results validate the mathematical models and demonstrate how the infection processes through perfusion via microfluidic platform led to an enhancement of adenoviral infection efficiency even at low MOIs. This was particularly evident at the longer time points, since the establishment of steady-state condition guaranteed a constant viral concentration close to cells, thus strengthening the efficiency of infection. Finally, we introduced the concept of effective MOI, a more appropriate variable for microfluidic infections that considers the number of adenoviruses in solution per cell at a certain time.     

Technology push and demand pull perspectives in innovation studies: Current findings and future research directions

This study updates the debate on the sources of innovation. Using techniques like factor analysis, multidimensional scaling, and pathfinder analysis, we examine the most influential articles that have dealt with the topic. Our analysis provides three main findings. The first more precisely highlights the role of demand as a source of innovation. The second illustrates how competences enable firms to match technology with demand and capitalize on technology and demand as sources of innovation. The third unveils a distinction between external and internal sources of innovations. The sources of innovation can be purely external or internally generated competences that enable the firm to integrate external knowledge within its boundaries. Our work contributes to the classic debate by providing a more granular understanding of how technology and demand interact. In discussing our findings, we link our framework to strategy, innovation and entrepreneurship studies that expressly call for a better understanding of technology and demand factors in value creation and capture.     

Return mobility and scientific productivity of researchers working abroad: The role of home country linkages

Through an analysis of 497 foreign researchers in Italy and Portugal we verify the impact of home linkages on return mobility choices and scientific productivity. We consider the presence of several different types of linkages of the researchers working abroad with their country of origin and control for the most relevant contextual factors (age, research area, position in the host country, etc.). The probability of return to their home country and scientific productivity in the host country are both higher for researchers that maintain home linkages. We conclude that the presence of home linkages directly benefits both countries in addition to the indirect benefit of expanding the scientific networks. Policy implications and suggestions for further research are discussed.     

Sex-Related Responses to Eccentric-Only Resistance Training in Knee-Extensors Muscle Strength and Architecture

Purpose: The present study aimed to investigate whether or not eccentric-only training induced different sex-related adaptations in vastus lateralis muscle architecture and knee extensors strength. Methods: Thirteen healthy women and 13 healthy men were recruited. Vastus lateralis pennation angle, fascicle length, and muscle thickness, as well as knee extensors eccentric, isometric, and concentric peak torque and one-repetition maximum (1RM) were measured. Both women and men underwent a unilateral iso-load knee-extension eccentric-only training with 120% of the concentric 1RM, consisting of 4 sets × 10 repetitions twice a week for a total of 8 weeks. Results: Pennation angle increased in women (+ 14%, 95% CI [10, 17], effect size [ES] = 1.54) but not in men (+ 5%, 95% CI [?1, 11], ES = 0.28), while fascicle length increased in both women (+ 7%, 95% CI [4, 10], ES = 1.02) and men (+ 12%, 95% CI [8, 16], ES = 1.82) and muscle thickness increased in women (+ 13%, 95% CI [8, 18], ES = 1.11) and men (+ 11%, 95% CI [7, 15], ES = 0.89). In both women and men, eccentric (18%, 95% CI [11, 25], ES = 0.96, and 16%, 95% CI [9, 22], ES = 0.82, respectively), isometric (17%, 95% CI [11, 23], ES = 0.53, and 17%, 95% CI [10, 24], ES = 0.62), concentric (12%, 95% CI [7, 16], ES = 0.49, and 9%, 95% CI [5, 13], ES = 0.42) peak torque and 1RM (10%, 95% CI [6, 14], ES = 0.53, and 10%, 95% CI [5, 15], ES = 0.50) similarly increased after the intervention. Conclusions: This study showed that the adaptations in strength are not sex-dependent, but the increases in pennation angle only in women suggest that the changes in muscle architecture may depend on sex.     

An international comparison of sectoral knowledge bases: persistence and integration in the pharmaceutical industry

This paper builds upon and extends existing studies of scientific and technological specialisation by proposing an analytical framework to compare sectoral knowledge bases across countries. It develops the concepts of knowledge persistence and knowledge integration as the relevant dimensions along which knowledge bases can be compared. Persistence is studied by analysing the evolution of specialisation over time. It hints at the cumulative, path dependent nature of learning processes. Integration is studied by analysing the evolution of specialisation across different typologies of research. It hints at the complex, non-linear interdependencies that link the scientific and technological domains. On the strength of an original database encompassing 630,000 peer-reviewed papers published between 1989 and 1996 in 11 chemistry and pharmacology-related fields across three types of research (i.e. basic, applied and development), it is argued that countries with high degrees of both persistence and integration (e.g. the US in pharmacology) are the most likely sources of useful research results for EU firms’ innovative efforts in the pharmaceutical sector. Also, some doubts are cast on the existence of a European paradox in pharmaceuticals.     

Touching epistemologies: meanings of average and variation in nursing practice

We present a study of the meanings of average and variation displayed by paediatric nurses. We trace how these meanings shape, and are shaped by, nurses' interpretations of trends in patient and population data. We suggest a theoretical framework for making sense of the data which compares and contrasts nurses' epistemology with that of official mathematics. Finally, we outline some provisional didactical implications.This revised version was published online in September 2005 with corrections to the Cover Date.     

Popular Protest Against Hungarian Symbols in Croatia (1883–1903). A Study in Visual History

The article investigates the visual dimension of popular protests in Habsburg Croatia at the end of the nineteenth and beginning of the twentieth century, reconstructing the history of a precise pattern of popular protest, i.e. anti-Hungarian unrests. Furthermore, the article explores the relationships that peasant masses established with some key national symbols, namely the Hungarian and Croatian flag, showing the multiple and contested meaning assigned to them by the members of the elite and the peasants. Second, the article shows how popular reception of these visual symbols changed during the examined period. The main issues addressed are therefore the mass nationalization and politicization of rural population in these regions, raising some general questions related to the symbolic language of social conflict.     

Teacher training by alternating classroom work and work analysis: from the perspective of a social conception of meaning and action

This article explores teacher training by the alternation of classroom work and work analysis using an approach based on a social conception of meaning and action. The advantage of this approach is that it allows the development of professional activity in preservice teachers (PTs) to be assessed by tracking how the reflective tools acquired in training evolve in work and/or work analysis situations. The concepts of ‘meaning’ and ‘expectation’ are helpful in discussing the empirical data from a research program designed to evaluate the potential for PTs’ professional development offered by the alternating work/analysis programs of French University Institutes of Teacher Training. The main conclusions concern the need to organize PTs’ professional experiences within a training network so that PTs are not left on their own to face the diverse and complex situations of daily professional exercise. The effective procedures are those that allow PTs to construct concrete and circumstance‐based expectations that the professional rules they have learned are still operational. These expectations help PTs to efficiently calibrate and interpret the meaning of their work experience, while also allowing them to prepare to act differently.     

Development of a scale of Sense of Community in university online courses

Creating a sense of community in online classes contributes to student retention and to their overall satisfaction with the course itself. This study aimed to develop a scale of sense of community of students attending online university courses. A series of ordinal exploratory factor analyses were conducted on data obtained from 839 students enrolled in Italian universities. Using an item analysis method, we were able to select the 36 most valid items from an original set of 60 items we had previously defined. These items are distributed across three related factors measuring membership, influence, and fulfillment of needs. This factorial structure replicates the McMillan and Chavis’s model of sense of community, upon the basis of which this scale was developed. The three factors presented good ordinal alpha and adequate convergent/divergent validity coefficients. The scale represents an efficient tool for the design, monitoring, and evaluation of online courses.