ISSCR standards for the use of human stem cells in basic research

The laboratory culture of human stem cells seeks to capture a cellular state as an in vitro surrogate of a biological system. For the results and outputs from this research to be accurate, meaningful, and durable, standards that ensure reproducibility and reliability of the data should be applied. Although such standards have been previously proposed for repositories and distribution centers, no widely accepted best practices exist for laboratory research with human pluripotent and tissue stem cells. To fill that void, the International Society for Stem Cell Research has developed a set of recommendations, including reporting criteria, for scientists in basic research laboratories. These criteria are designed to be technically and financially feasible and, when implemented, enhance the reproducibility and rigor of stem cell research

Validating the Course Experience Questionnaire in West Bengal higher secondary education

The Course Experience Questionnaire (CEQ) is a 36-item instrument that is intended to measure six different aspects of students’ perceptions of the academic quality of their programmes. It has been widely used in Western countries, and it has also been used in non-Western countries, including China, Hong Kong, Japan and Pakistan. Nevertheless, in the latter countries, it has sometimes not been possible to identify the full range of constructs that were supposed to be measured by the original CEQ. We translated the CEQ into Bengali and administered this to 552 science students at 15 higher secondary schools in West Bengal, India. A confirmatory factor analysis found that their responses provided a poor fit to the original six-factor model of the CEQ. An exploratory factor analysis identified just four constructs, which reflected good teaching, generic skills, student support and appropriate workload. The items with salient loadings on the four factors were used to construct four scales. The students’ scores on three of the four scales showed satisfactory levels of internal consistency. A factor analysis of their scores on all four scales yielded one overarching factor that could be interpreted as a measure of perceived academic quality. A reduced version of the CEQ consisting of the 30 items that constitute these four scales can be recommended as a measure of students’ perceptions of the academic quality of programmes in West Bengal

Delta Scuti Network observations of XX Pyx : detection of 22 pulsation modes and of short-term amplitude and frequency variations

We report multisite observations devoted to the main-sequence δ Scuti star XX Pyx, conducted as the 17th run of the Delta Scuti Network. Over 125 nights a total of 550 h of usable time-series photometric B- and V-filter data were acquired involving both photoelectric and CCD measurements at eight observatories spread around the world, which represents the most extensive single time-series for any pulsating star other than the Sun obtained so far. We describe our observations and reduction methods, and present the frequency analysis of our new data. First, we detect six new pulsation and five new combination frequencies in the star's light curves. We also discover evidence for amplitude and/or frequency variations of some of the modes during the observations. These can occur on time-scales as short as 20 d and show quite diverse behaviour. To take them into account in the frequency analysis, a so-called non-linear frequency analysis method was developed, allowing us to quantify the temporal variability of the modes and to compensate for it. Following that we continue the frequency search and we also incorporate published multisite observations. In this way, we reveal three more pulsation and two more combination frequencies. In the end, we report a total of 30 significant frequencies - 22 of which correspond to independent pulsation modes. This is the largest number of independent modes ever detected in the light curves of a δ Scuti star. The frequencies of the modes show preferred separations as already suggested by previous work on this star; they are also arranged in clear patterns. These results lead to a refinement of the stellar mean density (ṗ = 0.241 ± 0:008 ṗ ̛) and to a new constraint on the rotation rate of XX Pyx vrot = 1.1 ± 0.3d-ˡ: However, our attempts to identify the modes by pattern recognition failed. Moreover, mode identification from multicolour photometry failed as well because the high pulsation frequencies make this method unfavourable. The diverse behaviour of the amplitude and frequency variations of some of the modes leaves resonances as the only presently known possibility for their explanation