Block-and-break generation of microdroplets with fixed volume

We introduce a novel type of droplet generator that produces droplets of a volume set by the geometry of the droplet generator and not by the flow rates of the liquids. The generator consists of a classic T-junction with a bypass channel. This bypass directs the continuous fluid around the forming droplets, so that they can fill the space between the inlet of the dispersed phase and the exit of the bypass without breaking. Once filled, the dispersed phase blocks the exit of the bypass and is squeezed by the continuous fluid and broken off from the junction. We demonstrate the fixed-volume droplet generator for (i) the formation of monodisperse droplets from a source of varying flow rates, (ii) the formation of monodisperse droplets containing a gradation of solute concentration, and (iii) the parallel production of monodisperse droplets.     

Split genes

Contrary to what Jacques Monod affirmed in the 1960s, it is now known that what is true of the bacterium is not true of the elephant. In particular, it was discovered in 1977 that the genes of the higher organisms are split into segments, instead of being continuous as is the case with, for example, Escherichia coli. What is the significance of this split structure and how do organisms manage to gather together the useful parts of their genes and to eliminate those which are surplus? This article reviews what is already certain in this field and comments on the most recent prospects opened up by the discovery of genes ‘in pieces’.     

A guileful ruse: ISIS,media, and tactics of appropriation

When Islamic State in Iraq and Syria (ISIS), in the throes of territorial demise, laid claim to the deadliest mass shooting in US history, the 2017 Las Vegas shooting, pundits declared it a sign of desperation. This paper begins from a different premise: that the case simultaneously exposes how ISIS regularly appropriates rather than inspires violence and the limits of this tactic. An analysis of ISIS propaganda and three ISIS-attributed incidents reveals that the group’s ability to claim violence depends not on tactically rerouting media discourse, representation, or practice, but on taking these to their expected end, telling “us” exactly what we want to hear.     

Multimedia and interactivity in distance learning of resuscitation guidelines: a randomised controlled trial

The aim of the study was to conduct a comparative analysis of three forms of knowledge transfer online, taking into account the long-term knowledge growth rate and the satisfaction of students surveyed in respect to distance learning. The cohort of participants for this survey were students of the first degree, studying in the Emergency Medical Services. The authors created three e-learning courses in basic and advanced resuscitation procedures. The level of course participants’ satisfaction was analysed, as well as the knowledge growth rate measured three times: 7, 30 and 90 days, respectively, after finishing the course. The level of satisfaction in all the groups surveyed was comparable. The growth rate for knowledge was the highest in group C in the second and third survey, respectively (30 and 90 days after the end of the course), and a significant difference in favour of course C was demonstrated one month after finishing classes.     

Habitual physical activity levels and sedentary time of children in different childcare arrangements from a nationally representative sample of Canadian preschoolers

BackgroundChildren spend substantial time in childcare, and the reasons parents choose a particular childcare type may differ by family. However, little is known about how childcare type influences habitual (full day) activity levels among children. Therefore, exploring patterns between childcare type and habitual physical activity (PA) (i.e., light, moderate-to-vigorous PA (MVPA), and total PA) and sedentary time (ST) in young Canadian children is needed.MethodsA nationally representative sample of preschoolers from Cycles 3 and 4 of the Canadian Health Measures Survey was used in this cross-sectional study. Childcare type (e.g., center-based childcare, home-based childcare, home with parent, kindergarten) was reported by parents. Preschoolers wore an Actical accelerometer for 7 days. Device and population-spcific cut-points were applied to delineate PA intensities and ST. Population means and sample totals were calculated to examine average daily and hourly rates of activity.ResultsPreschoolers’ rates of MVPA and total PA from the 4 childcare arrangements ranged from 65.99 min/day to 74.62 min/day (5.48–6.18 min/h) and 274.20 min/day to 281.66 min/day 22.69–23.21 min/h), respectively, while ST ranged from 443.13 min/day to 460.57 min/day (36.80–37.31 min/h). No significant differences were observed in daily or hourly rates of activity.ConclusionThis study provides a snapshot of the levels of PA and ST among preschoolers in various childcare settings at a national level, with no differences observed in habitual activity levels based on childcare enrollment. Additional research is needed to clarify the relationship between young children's PA and childcare type, with consideration given to the quality of the childcare settings.     

Managers’ cognitive capabilities and perception of market research usefulness

The main purpose of this paper is to investigate the relationships between three theoretical constructs developed in the course of the study measuring: (a) managers' memory capacity, (b) information processing, as a part of general system of cognitive capabilities, and (c) their perception of market research usefulness. In particular, we diagnose managers' natural limitations associated with cognition which determine their capabilities to deal with the market research information storage and retrieval as well as research information processing. With this intention and theoretical assumption, we designed and implemented a two-phase process of research. In the first phase, based on the literature review; face-to-face in-depth interviews and a pilot study (a pretest) we developed measurement models for the proposed theoretical constructs. Next, we conducted quantitative research among 213 highly experienced managers working in multinational companies in a European country (Poland), where the sample included individuals who were responsible for planning strategic and tactical marketing activities. Based on the structural equation modeling as the analytical strategy, the empirical research results revealed that managers in business organizations due to limited cognitive capabilities such as lower-than-average memory capacity and poor information processing, develop wrong perceptions of the usefulness of market research. Managers, when faced with difficulties regarding information storage and retrieval, as well as information processing, react negatively towards that research. Finally, we explained the reasons as to why managers in companies perceive market research in a negative light, as well as presented the most important theoretical and managerial implications.     

OPINION RESEARCH AND THE FALL OF COMMUNISM: POLAND 1981-1990

The first polling organization in Eastern Europe was set upin the late 1950s in Warsaw. It did not happen accidentally;Poland had a long tradition of social research reaching backto the early 1920s. After the Stalinist period of the early1950s these traditions were continued by a new generation ofresearchers. This paper analyzes the development of opinionresearch centers and progress in the area of methodology. Twoproblems, very important for public opinion research in Polandas well as in the other East European countries, are stressedin the article: the complex relations between opinion pollingand political circumstances, and the scientific debates focusedon the reliability and accuracy of the survey findings.