One-dimensional transient finite difference model of an operational salinity gradient solar pond

This paper describes the modeling approach used to simulate the transient behavior of a salinity gradient solar pond. A system of finite difference equations are used to generate the time dependent temperature and salinity profiles within the pond. The stability of the pond, as determined by the capacity of the resulting salinity profile to suppress thermal convection within the primary gradient region of the pond, is continually monitored and when necessary adjustments are made to the thickness of the gradient zone. Results of the model are then compared to measurements taken during two representative seasonal periods at the University of Texas at El Paso's (UTEP's) research solar pond

Raising girls’ participation in A-level mathematics: initial findings from ‘good practice’ case studies

Fewer girls than boys in England participate in post-compulsory mathematics and the recent increase in popularity of Mathematics and Further Mathematics (FM) at age 16 has not changed the gender balance. Previous studies have shown the significance to girls of their mathematics lessons and teachers, of discursive co-constructions of masculinity and mathematics, of the range of careers associated with mathematics and science, and family ‘science capital’. This study identified four case-study schools and one Further Education (FE) college with unusually high participation by girls in mathematics A-level. Focus groups and lesson observations were used to explore factors relevant to girls’ participation. Common factors were: preparation for demanding mathematics during key stage 4, a departmental ethos which encouraged student-teacher interactions in and out of lessons, teachers who explicitly and repeatedly confirmed that girls would succeed at mathematics A-level, appreciation of mathematics as opening doors to many careers. Messages about FM were more restrictive but emphasised interest over unusual ability

Wider school effects of engaging with the Further Mathematics Support Programme to introduce Further Mathematics: Final Report

Case studies were conducted in four 11-18 schools where Further Mathematics (FM) A-level has recently been introduced with some input from the Further Mathematics Support Programme (FMSP). The aim was to probe teachers’ accounts of the range of effects of that introduction beyond the targeted FM students, so as to inform policy makers, other schools and teachers, potential students and their parents. Interviews with Heads of Departments and A-level teachers investigated any reported impact on teachers, structures, pedagogy and students at four points as the new course(s) developed. Intervening lesson observations served to elucidate and challenge the researchers’ understanding

Eukaryotic Transcription: What Does It Mean for a Gene to Be ‘on’?

Until recently, transcription could only be observed by measuring mRNA production of cell populations, thus obscuring the kinetics at the level of individual transcription events. A new study now shows that eukaryotic transcription, visualised in individual living cells, occurs in bursts — much as it does in prokaryotes

Protein synthesis molecule by molecule

Since the earliest days of molecular biology it has been known that even a seemingly uniform culture of bacteria is made up of cells very different from each other in terms of their levels of a given protein. This individuality has now finally been quantified at single-molecule resolution, as reported in two recent papers

VEGF guides angiogenic sprouting utilizing endothelial tip cell filopodia

Vascular endothelial growth factor (VEGF-A) is a major regulator of blood vessel formation and function. it controls several processes in endothelial cells, such as proliferation, survival, and migration, but it is not known how these are coordinately regulated to result in more complex morphogenetic events, such as tubular sprouting, fusion, and network formation. We show here that VEGF-A controls angiogenic sprouting in the early postnatal retina by guiding filopodial extension from specialized endothelial cells situated at the tips of the vascular sprouts. The tip cells respond to VEGF-A only by guided migration; the proliferative response to VEGF-A occurs in the sprout stalks. These two cellular responses are both mediated by agonistic activity of VEGF-A on VEGF receptor 2. Whereas tip cell migration depends on a gradient of VEGF-A, proliferation is regulated by its concentration. Thus, vessel patterning during retinal angiogenesis depends on the balance between two different qualities of the extracellular VEGF-A distribution, which regulate distinct cellular responses in defined populations of endothelial cells

Effect of low-pressure storage on the quality of green capsicums (<i>Capsicum annum L.</i>)

Green capsicums (Capsicum annum L.) were stored under low pressure (4 kPa) at 10°C for 5 and 11 days with 100% RH. The results showed that the incidence of stem decay under low pressure storage for 5 and 11 days and storage at ambient atmosphere at 20°C for three days lower compared to fruits that were stored at regular atmosphere at 10°C. Fruit that had been stored at low pressure at 10°C had no symptoms of flesh rots for up to 11 days, whilst fruit which had been stored at regular atmosphere at 10°C had 6% flesh rots after 11 days storage at 10°C.There was no difference in flesh firmness and colour retention between fruits stored at low pressure and regular pressure at 10°C. Capsicums stored at low pressure had higher overall acceptability compared to fruit that were stored at regular atmosphere at 10°C. These results demonstrate the potential of low pressure storage as an effective technique to manage capsicum fruit quality, however there was no additional benefit when fruits were stored at low pressure for more than 5 days

The application of low pressure storage to maintain the quality of zucchinis

Zucchini (Cucurbita pepo var. cylindrica) were stored at low pressure (4 kPa) at 10°C at 100% relative humidity for 11 days. Fruit quality was examined upon removal and after being transferred to normal atmosphere (101 kPa) at 20°C for three days. Zucchinis stored at low pressure exhibited a 50% reduction in stem-end browning compared with fruit stored at atmospheric pressure (101 kPa) at 10°C. The benefit of low pressure treatment was maintained after the additional three days storage at normal atmospheric pressure at 20°C. Indeed, low pressure treated fruit transferred to regular atmosphere 20°C for three days possessed a significantly lower incidence of postharvest rot compared to fruit stored at regular atmospheric pressure at 10°C. Zucchinis stored at low pressure showed higher levels of acceptability (28% and 36%, respectively) compared to fruit stored at regular atmospheres at 10°C for both assessment times.<br/

Twelve month follow-up on a randomised controlled trial of relaxation training for post-stroke anxiety

© The Author(s) 2016. Objective: To follow up participants in a randomised controlled trial of relaxation training for anxiety after stroke at 12 months. Design: Twelve month follow-up to a randomised controlled trial, in which the control group also received treatment. Setting: Community. Participants: Fifteen of twenty one original participants with post-stroke anxiety participated in a one year follow-up study. Interventions: A self-help autogenic relaxation CD listened to five times a week for one month, immediately in the intervention group and after three months in the control group. Main measures: Hospital Anxiety and Depression Scale-Anxiety subscale and the Telephone Interview of Cognitive Status for inclusion. Hospital Anxiety and Depression Scale-Anxiety subscale for outcome. All measures were administered by phone. Results: Anxiety ratings reduced significantly between pre and post-intervention, and between pre-intervention and one year follow-up (‡2(2) = 22.29, p < 0.001). Conclusions: Reductions in anxiety in stroke survivors who received a self-help autogenic relaxation CD appear to be maintained after one year